• Korean Journal of Environmental Biology
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• v.20 no.4
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• pp.366-377
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• 2002

This study investigated the ecological environment of Dongguneung, which royal tombs of the Joseon Dynasty aye in. The aim of this study is to do an effective preservation, management and restoration of the royal tomb and garden of the Joseon Dynasty distributed in Seoul and Kyunggi Province through using the data of Dongguneung. In general, Dongguneung contains the predominant Oak class such as Quercus serrata-Quercus mongolica community, while a flatland surrounding its control office, which is often flooded with the rainy season in summer, is mainly Alnus japonica community, Pinus densiflora community ranges around the royal tomb. The subcommunity of Quercus serrata -Quereus mongolica community is distributed into Robinia pseudo-acacia, Pinus rigida, Pinus koraiensis, Carpinus laxiflora and typical subcommunity and so on. In particular, Robinia pseudo -acacia, Pinus rigida and Pinus koraiensis subcommunity, and Alnus japonica community were forested. The soil class of Dongguneung was mainly a sandy loam and its pH was an average of 4.67 (from 4.36 to 5.68). The content of heavy metals including Cu, Pb and Zn etc. in the soil was about twice as much as the natural content in the forest soil. The content of organism and total nitrogen in the topsoil layer was the average of 4.87% and 0.21% respectively, slightly higher than those (organism； 4.55%, total nitrogen； 0.20%) of the forest soil generated from granite bedrock. Cation exchange capacity as the indicator of soil fertility was 15.0 cmol $kg^{-1}$, higher than that in the granite forest soil. However among base exchangeable cations, contents of $Ca^{2+}$ (2.07 cmol $kg^{-1}$), $Mg^{2+}$ (0.40 cmol $kg^{-1}$) and K+ (0.25 cmol $kg^{-1}$) were slightly lower than that. The above results could reflect the need of soil fertilization and liming for the improvement of nutritional status and buffer process.

• Journal of Life Science
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• v.27 no.2
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• pp.202-210
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• 2017

As an effort to find a potential biopreservative, we isolated bacterial strains producing bacteriocin from fermented foods. A strain was finally selected and characteristics of the bacteriocin were investigated. The selected strain was identified as Bacillus subtilis E9-1 based on the 16S rRNA gene analysis. The culture supernatant of B. subtilis E9-1 showed antimicrobial activity against Gram-positive bacteria. Subtilisin A, ${\alpha}$-chymotrypsin, trypsin and proteinase K inactivated the antimicrobial activity, which means its proteinaceous nature, a bacteriocin. The bacteriocin activity was fully retained at the pH range from 2.0 to 8.0 and stable at up to $100^{\circ}C$ for 60 min. Solvents such as ethanol, isopropanol and methanol had no effect on the antimicrobial activity at the concentration of 100% but acetone and acetonitrile reduced the activity at up to 100% concentration. Cell growth of four indicator strains was dramatically decreased in dose-dependent manner. Listeria monocytogenes was the most sensitive, but Enterococcus faecium was the most resistant. Bacillus cereus and Staphylococcus aureus showed the medium sensitivity. The bacteriocin showed its antimicrobial activity against B. cereus and L. monocytogenes via bactericidal action. The number of viable cells of L. monocytogenes started to reduce after addition of bacteriocin to the minced beef. The bacteriocin was purified through acetone concentration, gel filtration chromatography and RP-HPLC. The whole purification step led to a 6.82 fold increase in the specific activity and 6% yield of bacteriocin activity. The molecular weight of the purified bacteriocin was determined to be 3.3 kDa by MALDI-TOF/TOF mass spectrometry.

• Journal of the Korean Chemical Society
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• v.54 no.5
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• pp.556-566
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• 2010

A new kinetic spectrophotometric method is developed for the measurement of Mn(II) in natural water samples. The method is based on the catalytic effect of Mn(II) with the oxidation of Gallocyanin by $KIO_4$ using nitrilotriacetic acid (NTA) as an activation reagent at 620 nm. The optimum conditions obtained are $4.00{\times}1^{-5}\;M$ Gallocyanin, $KIO_4$, $1.00{\times}10^{-4}\;M$ NTA, 0.1 M HAc/NaAc buffer of pH = 3.50, the reaction time of 5 min and the temperature of $30^{\circ}C$. Under the optimum conditions, the proposed method allows the measurement of Mn(II) in a range of $0.1\;-\;4.0\;ng\;mL^{-1}$ and with a detection limit of down to $0.025\;ng\;mL^{-1}$. The recovery efficiency in measuring the standard Mn(II) solution is in a range of 98.5 - 102%, and the RSD is in a range of 0.76 - 1.25%. The newly developed kinetic method has been successfully applied to the measurement of Mn(II) in both some environmental water samples and certified standard reference river water sample, JAC-0031 with satisfying results. Moreover, few cations and anions interfere with the measurement of Mn(II). Compared with the other catalytic-kinetic methods and instrumental methods, the proposed kinetic method shows fairly good selectivity and sensitivity, low cost, cheapness, low detection limit and rapidity. It can easily and successfully be applied to the real water samples with relatively low salt content and complex matrices such as bottled drinking water, cold and hot spring waters, lake water, river water samples.

• Journal of the Korean earth science society
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• v.43 no.1
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• pp.91-109
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• 2022

The ocean is a significant sink for atmospheric anthropogenic CO₂, absorbing one-third of the total CO₂ emitted by human activities. In return, oceans have experienced significant declines in seawater pH and the aragonite saturation state also called ocean acidification. This study evaluates the distribution of aragonite saturation state, an indicator to assess the potential threat from ocean acidification, by combining newly obtained data from the west coast of South Korea with previous datasets covering the Yellow Sea, East Sea, northern South China Sea, and southeast coast of South Korea. In general, offshore waters absorb atmospheric CO₂; however, most of the collected water samples show aragonite oversaturation. On the southeast coast, the aragonite saturation state was significantly affected by river discharge and associated variables, such as freshwater input with nutrients, seasonal stratification, biological carbon fixation, and bacterial remineralization. In summer, hypoxia and mixing with relatively acidic freshwater made the Jinhae and Gwangyang Bays undersaturated with respect to aragonite, possibly threatening marine organisms with CaCO₃ shells. However, widespread aragonite undersaturation was not observed on the west coast, which receives considerable river water discharge. In addition, occasional upwelling events may have worsened the ocean acidification in the southwestern part of the East Sea. These results highlight the importance of investigating site-specific ocean acidification processes in coastal waters. Along with the above-mentioned seasonal factors, the dissolution of atmospheric CO₂ and the deposition of atmospheric acidic substances will continue to reduce the aragonite saturation state in Korean waters. To protect marine ecosystems and resources, an ocean acidification monitoring program should be established for Korean waters.

• Journal of Food Hygiene and Safety
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• v.28 no.4
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• pp.324-329
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• 2013

This study investigated and evaluated contamination levels of bacteria on tomatoes at farms stage to evaluate potential hazards associated with fresh tomatoes. A total of 170 samples, 90 samples from 5 sampling sites from 18 farms and 80 samples from 1 sampling site from 4 farms every month for four months, were analyzed to enumerate aerobic bacterial counts, coliforms, E. coli, Bacillus cereus, Staphylococcus aureus, Escherichia coli, E. coli O157:H7, Salmonella spp., and Listeria monocytogenes. Aerobic bacterial counts ranged from 0.48 to 6.15 Log CFU/g, with the lowest and the highest bacterial cell counts recorded for A site and E site, respectively. Thirty five percent of the samples from the E site contained more than 2 Log CFU/g. Six samples (6.6%) of 90 samples contained B. cereus less than 1 Log CFU/g. In addition, the contamination level of indicator bacteria and B. cereus in tomatoes were higher on March than on April, May and June (P < 0.05). S. aureus, E. coli, E. coli O157:H7, Salmonella spp. and L. monocytogenes were not detected in the tomato samples. The microbial contamination levels of tomatoes determined in this study may be used as the data for microbiological risk assessment.

• Tuberculosis and Respiratory Diseases
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• v.49 no.6
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• pp.733-739
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• 2000

Background : Pleural eosinophilia is rare and commonly considered to be an indicator of good prognosis. The diagnostic significance of eosinophilic pleural effusions remains controversial despite a century of observation and discussion. This study was conducted to assess the prevalence of eosinophilia in 446 consecutive samples of pleural fluid, to review the cause of eosinophilic pleural effusion and to determine whether the presence of eosinophils increases the likehood of benign conditions. Method : A retrospective analysis was performed upon patients that underwent first thoracentesis due to pleural effusion between January 1999 and December 1999. Results : Eosinophilic pleural effusions were identified in 24 of the 446 patients (5.4%). Malignancy, parapneumonic effusion and tuberculosis were determined the major causes of pleural effusion (80.6%). Malignancy was diagnosed as frequently in eosinophilic effusions as in non-eosinophilic effusions (54.2% vs 50.5%, p=0.725). No difference was found in the prevalence of eosinophilic and non-eosinophilic effusion according to the etiology. The mean blood eosinophil ratio in patients with eosinophilic pleural effusion was 5.4% and no significant correlation existed between the blood and pleural eosinophilic count. Conclusion : Pleural eosinophilia is not helpful for differentiating benign and malignant etiology and is not related with bood eosinophilia or repeated tapping.

• Journal of Soil and Groundwater Environment
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• v.11 no.3
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• pp.31-42
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• 2006

Drought indices, such as PDSI (palmer Drought Severity Index), SWSI (Surface Water Supply Index) and SPI (Standardized Precipitation Index), have been developed to assess and forecast an intensity of drought. To find the applicability of groundwater level data to a drought assessment, a correlation analysis between SPI and groundwater levels was conducted for each time series at a drought season in 2001. The comparative results between SPI and groundwater levels of shallow wells of three national groundwater monitoring stations, Chungju Gageum, Yangpyung Gaegun, and Yeongju Munjeong, show that these two factors are highly correlated. In case of SPI with a duration of 1 month, cross-correlation coefficients between two factors are 0.843 at Chungju Gageum, 0.825 at Yangpyung Gaegun, and 0.737 at Yeongju Munjeong. The time lag between peak values of two factors is nearly zero in case of SPI with a duration of 1 month, which means that groundwater level fluctuation is similar to SPI values. Moreover, in case of SPI with a duration of 3 month, it is found that groundwater level can be a leading indicator to predict the SPI values I week later. Some of the national groundwater monitoring stations can be designated as DIW (Drought Index Well) based on the detailed survey of site characteristics and also new DIWs need to be drilled to assess and forecast the drought in this country.

• Korean Journal of Veterinary Research
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• v.41 no.4
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• pp.571-578
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• 2001

To evaluate if the apoptotic fragment assay could be used to estimate the dose prediction after radiation exposure, we examined apoptotic mouse crypt cells per 1,000 cells after whole body $^{60}Co$ $\gamma$-rays and 50MeV ($p{\rightarrow}Be^+$) cyclotron fast neutron irradiation in the range of 0.25 to 1 Gy, respectively. The incidence of apoptotic cell death rose steeply at very low doses up to 1 Gy, and radiation at all doses tigger rapid changes in crypt cells in stem cell region. These data suggest that apoptosis may play an important role in homeostasis of damaged radiosensitive target organ by removing damaged cells. The curve of dose-effect relationship for the data of apoptotic fragments was obtained by the linear-quadratic model $y=0.18+(9.728{\pm}0.887)D+(-4.727{\pm}1.033)D^2$ ($r^2=0.984$) after $\gamma$-rays irradiation, while $y=0.18+(5.125{\pm}0.601)D+(-2.652{\pm}0.7000)D^2$ ($r^2=0.970$) after neutrons in mice. The dose-response curves were linear-quadratic, and a significant dose-response relationship was found between the frequency of apoptotic cell and dose. These data show a trend towards increase of the numbers of apoptotic crypt cells with increasing dose. Both the time course and the radiation dose-response curve for high and low linear energy transfer (LET) radiation modalities were similar. The relative biological effectiveness (RBE) value for crypt cells was 2.072. In addition, there were significant peaks on apoptosis induction at 4 and 6h after irradiation, and the morpholoigcal findings of the irradiated groups were typical apoptotic fragments in crypt cells that were hardly observed in the control group. Thus, apoptosis in crypt cells could be a useful in vivo model for studying radio-protective drug sensitivity or screening test, microdosimetric indicator and radiation-induced target organ injury. Since the apoptotic fragment assay is simple, rapid and reproducible in the range of 0.25 to 1 Gy, it will also be a good tool for evaluating the dose response of radiation-induced organ damage in vivo and provide a potentially valuable biodosimetry for the early dose prediction after accidental exposure.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.4
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• pp.288-295
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• 2010

Metal exposure experiments using polychaete (Perinereis nuntia) as a bio-indicator of trace metals contamination were conducted to evaluate the bioaccumulation and the biomarkers responses such as metallothionein-like protein (MTLPs) and glutathione S-transferase (GST) which was simultaneously exposed to Cadmium (Cd) and Copper (Cu). Cu and Cd concentrations in polychaete were enhanced with increasing exposure time and their concentrations of aqueous medium. Initial accumulation of Cd was higher than that of Cu. Our results showed that the bioaccumulation of Cu and Cd were prohibited, especially at higher Cu levels, suggesting the different cellular uptake mechanisms when Cu and Cd are co-exist. Net accumulation rate of Cu was declined with exposure time but it did not show any significant change for Cd. Although the highest MTLPs concentration was observed at 6 hr of exposure time, it did not show any significant change related to exposure times and metals concentrations. An increase of GST activity tended to increase as a function of exposure time and metals concentrations. And GST activities in P. nuntia have similar tendency with bioconcentration factors in high concentration of Cu (treatment group IV) at post 24 h of exposure. Our results provide new information of the bioaccumulation and biomarker responses to understand the effects of co-existing contaminants (Cu and Cd) using polychaete. Further studies are required to elucidate the bioaccumulation and biomarkers responses for various contaminants.

• Journal of Korean Society of Forest Science
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• v.84 no.2
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• pp.266-274
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• 1995

Vegetational data from 62 quadrats of Pinus densiflora for. erecta and Chunyang-type of Pines densiflora forests were analyzed by using two multivariate methods : TWo-way INdicator Species ANalysis(TWINSPAN) for classification and Detrended Canonical Correspondence Analysis(DCCA) for ordination. The dominant tree species of Pinus densiflora for. erecta communities were found in the order of Pines densiflora for. erecta, Quercus mongolica, Quercus variabilis, Lindera obtusiloba, Fraxinus rhynchophylla, and Rhus trichocapa. The dominant tree species of Chunyang -type of Pinus densiflora communities were Quercue variabilis. Quercue mongolica, Fraxiraus sieboldiana, Styrax obassia, and Quercus serrata. The forest vegetation of Pinus densiflora was classified into Quercars variabilis-Styrax obassia. Quercus variabilis Quercus variabilis-Quercus mongolica, and Quercue mongolica communities according to TWINSPAN. Pinus densiflora for. erecta community was distributed in the good nutrition area of total nitrogen. organic matter, $K^+$, $Ca^{{+}+}$, $Mg^{{+}+}$, and canon exchange capacity, while Chunyang type of Pinus densiflora community in the good nutrition area of $P_2O_5$. The relationship between the distribution of dominant communities for forest vegetation and soil condition in Pinus densiflora communities was investigated by analysing the elevation and soil nutrition gradients. Quercus mongolica community was distributed in the high elevation and good nutrition area of total nitrogen, organic matter, and ration exchange capacity, while Quercus variabilis community was distributed in the low elevation and poor nutrition area of total nitrogen, organic matter, and ration exchange capacity. Quercus variabilis Styrax obassia and Quercus variabilis-Quercus mongolica community was distributed en the medium elevation and medium nutrition area.