• Korean Journal of Microbiology
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• v.53 no.2
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• pp.83-96
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• 2017

A constructed sea stream in Yeongdo, Busan, Republic of Korea is mostly static due to the lifted stream bed and tidal characters, and receives domestic wastewater nearby, causing a consistent odor production and water quality degradation. Bioaugmentation of a microbial consortium was proposed as an effective and economical restoration technology to restore the polluted stream. The microbial consortium activated on site was augmented on a periodic basis (7~10 days) into the most polluted site (Site 2) which was chosen considering the pollution level and tidal movement. Physicochemical parameters of water qualities were monitored including pH, temperature, DO, ORP, SS, COD, T-N, and T-P. COD and microbial community analyses of the sediments were also performed. A significant reduction in SS, COD, T-N, and COD (sediment) at Site 2 occurred showing their removal rates 51%, 58% and 27% and 35%, respectively, in 13 months while T-P increased by 47%. In most of the test sites, population densities of sulfate reducing bacterial (SRB) groups (Desulfobacteraceae_uc_s, Desulfobacterales_uc_s, Desulfuromonadaceae_uc_s, Desulfuromonas_g1_uc, and Desulfobacter postgatei) and Anaerolinaeles was observed to generally decrease after the bioaugmentation while those of Gamma-proteobacteria (NOR5-6B_s and NOR5-6A_s), Bacteroidales_uc_s, and Flavobacteriales_uc_s appeared to generally increase. Aerobic microbial communities (Flavobacteriaceae_uc_s) were dominant in St. 4 that showed the highest level of DO and least level of COD. These microbial communities could be used as an indicator organism to monitor the restoration process. The alpha diversity indices (OTUs, Chao1, and Shannon) of microbial communities generally decreased after the augmentation. Fast uniFrac analysis of all the samples of different sites and dates showed that there was a similarity in the microbial community structures regardless of samples as the augmentation advanced in comparison with before- and early bioaugmentation event, indicating occurrence of changing of the indigenous microbial community structures. It was concluded that the bioaugmentation could improve the polluted water quality and simultaneously change the microbial community structures via their niche changes. This in situ remediation technology will contribute to an eco-friendly and economically cleaning up of polluted streams of brine water and freshwater.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.1
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• pp.23-32
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• 2010

The capacity of natural purification was limited by the interruption of natural flow and the problems such as eutrophication were occurred by nutritive salts accumulation in stagnant stream. Moreover, the inflow of non-point sources causes non-degradable materials to increase in stagnant stream. In this study, an upflow biological activated carbon (BAC) biofilm process comprised of anoxic, aerobic 1, and aerobic 2 reactors were introduced for treatment of stagnant stream and SS, $BOD_5$, $COD_{Mn}$, $COD_{Cr}$, TN, and TP were monitored in the upflow BAC biofilm reactors with continuous cycling. In order to simulate stagnant stream, the lake water of amusement park and golf course were stored as influent in a tank of $2m^3$ and hydraulic retention time (HRT) was changed into 6, 4, and 2 hours. At HRT 4hr and the lake water of amusement park as influent, the removal efficiencies of SS, $BOD_5$, $COD_{Mn}$, $COD_{Cr}$, TN, and TP showed the best water quality improvement and were 69.8, 83.0, 91.3, 74.1, 74.7, and 88.9%, respectively. At HRT 4hr and the lake water of golf course as influent, the removal efficiencies of SS, $BOD_5$, $COD_{Mn}$, $COD_{Cr}$, TN and TP were 78.5, 78.0, 80.2, 74.9, 55.6 and 97.5%, respectively. As the results of polymerase chain reaction - denaturing gel gradient electrophoresis (PCR-DGGE), microbial community was different depending on influent type. Fluorescence in situ hybridization (FISH) showed that nitrifying bacteria was dominant at HRT 4 hr. The biomass amount and microbial activities by INT-DHA test were not decrease even at lower HRT condition. In this study, the upflow BAC biofilm process would be considered to the water quality improvement of stagnant stream.

• Radiation Oncology Journal
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• v.21 no.4
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• pp.315-321
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• 2003

Purpose: This study was peformed to Investigate apoptosis by radiation In the developing fetal rat brain. Materials and Methods: Fetal blains were Irradiated In utero between the 17th and 19th days of fetal life (El7-19) by linear accelerator. A dose of Irradiation ranging from 1 Gy to 4 Gy was used to evaluate dose dependency. To test time dependency the ra)s were Irradiated with 2 Gy and then the fetal brain specimens were removed at variable 41me course; 1, 3, 5, 12 and 24 hours after the onset of irradiation. Immunohistochemlcal staining using in situ 707-mediated dUTP nick end labelling (TUNEL) technlfue was used for apoptotic cells. The cerebral cortex, including three zones on coriicai zone (Cf). Intermediate zone (if), and ventricular zone (VZ), was examined. Results : TUNEL positive cells revealed typical features of apoptotic cells under light microscope In the fetal rat cerebral cortex. Apoptotic cells were not found In the cerebral cortex of non-Irradiated fetal rats, but did appear In the entire cerebral cortex after 1 Gy Irradiation, and were more expensive at the ventricular and Intermediate zones than at the cortical zone. The extent of apoptosis was Increased with Increasing doses of radiation. Apoptosis reached the peak at S hours after the onset of 2 Gy Irradiation and persisted until 24 hours. Conclusion: Typical morphological features of apoplosis by irradiation were observed In the developing fetal rat cerebral cortex. It was more extensive at the ventricular and Intermediate zones than at the cortical zone, which suggested that stem cells or early differentiated cells are more radiosensitive than differentiated cells of the cortical zone.

• The Journal of Engineering Geology
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• v.21 no.2
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• pp.133-145
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• 2011

Unsaturated soil column tests were performed for weathered gneiss soil and weathered granite soil to assess the relationship between infiltration velocity and rainfall condition for different rainfall durations and for multiple rainfall events separated by dry periods of various lengths (herein, 'rainfall break duration'). The volumetric water content was measured using TDR (Time Domain Reflectometry) sensors at regular time intervals. For the column tests, rainfall intensity was 20 mm/h and we varied the rainfall duration and rainfall break duration. The unit weight of weathered gneiss soil was designed 1.21 $g/cm^3$, which is lower than the in situ unit weight without overflow in the column. The in situ unit weight for weathered granite soil was designed 1.35 $g/cm^3$. The initial infiltration velocity of precipitation for the two weathered soils under total amount of rainfall as much as 200 mm conditions was $2.090{\times}10^{-3}$ to $2.854{\times}10^{-3}$ cm/s and $1.692{\times}10^{-3}$ to $2.012{\times}10^{-3}$ cm/s, respectively. These rates are higher than the repeated-infiltration velocities of precipitation under total amount of rainfall as much as 100 mm conditions ($1.309{\times}10^{-3}$ to $1.871{\times}10^{-3}$ cm/s and $1.175{\times}10^{-3}$ to $1.581{\times}10^{-3}$ cm/s, respectively), because the amount of precipitation under 200 mm conditions is more than that under 100 mm conditions. The repeated-infiltration velocities of weathered gneiss soil and weathered granite soil were $1.309{\times}10^{-3}$ to $2.854{\times}10^{-3}$ cm/s and $1.175{\times}10^{-3}$ to $2.012{\times}10^{-3}$ cm/s, respectively, being higher than the first-infiltration velocities ($1.307{\times}10^{-2}$ to $1.718{\times}10^{-2}$ cm/s and $1.789{\times}10^{-2}$ to $2.070{\times}10^{-2}$ cm/s, respectively). The results reflect the effect of reduced matric suction due to a reduction in the amount of air in the soil.

• Journal of the Korean Geotechnical Society
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• v.38 no.11
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• pp.43-54
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• 2022

The settlement at the railroad foundation is often the leading cause of track irregularity and potential derailment. The control of such deformation is considered necessary in track maintenance practice. Nevertheless, the monitoring process performed by in situ surveying requires an excessive amount of manpower and cost. The InSAR, a remote sensing technique by RADAR satellite, is used to overcome such a burden. The PS-InSAR technique is preferred for a long-term precise monitoring method. However, this study aims to obtain relatively brief analysis results from only two satellite images using the D-InSAR technique, while a minimum of 25 images are required for PS-InSAR. This study verifies the precision of D-InSAR within a few millimeters by inspecting railroad facilities and land settlements in Korea Railroad Research Institute's test track with images from TerraSAR-X Satellite. Multiple corner reflectors were adopted and installed on an embankment and the building roof to raise the surface reflectivity. Those reflectors were slightly adjusted periodically to verify the detecting performance. The results revealed the optimum distance between corner reflectors. Further, the deformation of railway tracks, slopes, and concrete structures was analyzed successively. In conclusion, this study indicates that the D-InSAR technique effectively monitors the short-term deformation of a broad area such as railway structures.

• Toxicological Research
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• v.23 no.3
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• pp.279-287
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• 2007

Copper (Cu) is an essential trace element indispensable for brain development and function; either excess or deficiency in Cu can cause brain malfunction. While it is known that Cu and Fe homeostasis are strictly regulated in the brain, the question as to how systemic Fe status may influence brain Cu distribution was poorly understood. This study was designed to test the hypothesis that dietary Fe condition affects Cu transport into the brain, leading to an altered brain distribution of Cu. Rats were divided into 3 groups; an Fe-deficient (Fe-D) group which received an Fe-D diet ($3{\sim}5 mg$ Fe/kg), a control group that was fed with normal diet (35mg Fe/kg), and an Fe-overload group whose diet contained an Fe-O diet (20g carbonyl Fe/kg). Following a 4-week treatment, the concentration of Cu/Fe in serum, CSF (cerebrospinal fluid) and brain were determined by AAS, and the uptake rates of Cu into choroids plexus (CP), CSF, brain capillary and parenchyma were determined by an in situ brain perfusion, followed by capillary depletion. In Fe-D and Fe-O, serum Fe level decreased by 91% (p<0.01) and increased by 131% (p<0.01), respectively, in comparison to controls. Fe concentrations in all brain regions tested (frontal cortex, striatum, hippocampus, mid brain, and cerebellum) were lower than those of controls in Fe-D rats (p<0.05), but not changed in Fe-O rats. In Fe-D animals, serum and CSF Cu were not affected, while brain Cu levels in all tested regions (frontal cortex, striatum, hippocampus, mid brain, and cerebellum) were significantly increased (p<0.05). Likewise, the unidirectional transport rate constants $(K_{in})$ of Cu in CP, CSF, brain capillary and parenchyma were significantly increased (p<0.05) in the Fe-D rats. In contrast, with Fe-O, serum, CSF and brain Cu concentrations were significantly decreased as compared to controls (p<0.05). Cu transport was no significant change of Cu transport of serum in Fe-O rats. The mRNA levels of five Cu-related transporters were not affected by Fe status except DMT1 in the CP, which was increased in Fe-D and decreased in Fe-O. Our data suggest that Cu transport into brain and ensuing brain Cu levels are regulated by systemic Fe status. Fe deficiency appears to augment Cu transport by brain barriers, leading to an accumulation of Cu in brain parenchyma.

• The Journal of the Korean life insurance medical association
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• v.25
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• pp.63-77
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• 2006

The definition of 'critical cancer' in critical insurance(CI) is more insurance meanings than medical meanings. The difference between critical cancer of insurance and critical cancer of medical cancer is made difficult problem to the underwriting of insurer, contractor and medical doctor. The limited factors of underwriting in critical cancer of critical insurance as follows: (1) the limitation factors in the definition of 1st item critical cancer in CI 1) the definition differences of meanings in insurer, contractor, and medical doctor 2) the meanings of "the table of malignance" 3) the definition difference between 'critical cancer' and 'a large of medical expense cancer' (2) the limitation factors in the definition of second item critical cancer in CI 1) The limitation in the change of cancer character 2) The missing malignancy in pathological result due to localized cancer 3) The differences in the test result of hospital (3) the limitation factors in the definition of third item critical cancer in CI. 1) the lower items disobey the higher items 2) clinical malignancy of benign cancer pathologically 3) others: (1) low grade of malignant melanoma (2) early prostate cancer. (3) malignancy related HIV (4) all skin cancer excepted malignant melanoma (5) accepted clinically and a medical certificate by medical doctor as critical cancer of premalignant lesion, carcinoma-in-situ, and borderline cancer.

• Korean Journal of Radiology
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• v.20 no.1
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• pp.58-68
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• 2019

Objective: To compare digital breast tomosynthesis (DBT) and conventional full-field digital mammography (FFDM) in the detectability of breast cancers in patients with dense breast tissue, and to determine the influencing factors in the detection of breast cancers using the two techniques. Materials and Methods: Three blinded radiologists independently graded cancer detectability of 300 breast cancers (288 women with dense breasts) on DBT and conventional FFDM images, retrospectively. Hormone status, histologic grade, T stage, and breast cancer subtype were recorded to identify factors affecting cancer detectability. The Wilcoxon signed-rank test was used to compare cancer detectability by DBT and conventional FFDM. Fisher's exact tests were used to determine differences in cancer characteristics between detectability groups. Kruskal-Wallis tests were used to determine whether the detectability score differed according to cancer characteristics. Results: Forty breast cancers (13.3%) were detectable only with DBT; 191 (63.7%) breast cancers were detected with both FFDM and DBT, and 69 (23%) were not detected with either. Cancer detectability scores were significantly higher for DBT than for conventional FFDM (median score, 6; range, 0-6; p < 0.001). The DBT-only cancer group had more invasive lobular-type breast cancers (22.5%) than the other two groups (i.e., cancer detected on both types of image [both-detected group], 5.2%; cancer not detected on either type of image [both-non-detected group], 7.3%), and less detectability of ductal carcinoma in situ (5% vs. 16.8% [both-detected group] vs. 27.5% [both-non-detected group]). Low-grade cancers were more often detected in the DBT-only group than in the both-detected group (22.5% vs. 10%, p = 0.026). Human epidermal growth factor receptor-2 (HER-2)-negative cancers were more often detected in the DBT-only group than in the both-detected group (92.3% vs. 70.5%, p = 0.004). Cancers surrounded by mostly glandular tissue were detected less often in the DBT only group than in the both-non-detected group (10% vs. 31.9%, p = 0.016). DBT cancer detectability scores were significantly associated with cancer type (p = 0.012), histologic grade (p = 0.013), T and N stage (p = 0.001, p = 0.024), proportion of glandular tissue surrounding lesions (p = 0.013), and lesion type (p < 0.001). Conclusion: Invasive lobular, low-grade, or HER-2-negative cancer is more detectable with DBT than with conventional FFDM in patients with dense breasts, but cancers surrounded by mostly glandular tissue might be missed with both techniques.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3C
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• pp.187-196
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• 2008

An earthquake of magnitude 5.0 occurred at Ssang-gye-sa, a Buddhist temple in Jirisan, located near the southern border of the Korean peninsula on 4 July 1936. It resulted in severe damage of several buildings and structures in Ssang-gye-sa. Particularly, the top component of a five-story stone pagoda in the temple was tipped over and fell down during the earthquake. This earthquake damage case would be usefully applied to estimating the intensity of ground motion in the Korean peninsula, a moderate seismicity region, where strong motion has never been recorded with the exception of historic seismic events. In order to estimate the local site effects and the corresponding ground motion at Ssang-gye-sa site, intensive site investigations including borehole drilling and in-situ seismic tests such as crosshole and SASW tests were performed in the temple area. Based on the site characteristics, site-specific seismic response analyses using various input motions were conducted for a representative Ssang-gye-sa site by means of both one-dimensional equivalent-linear and nonlinear methods with six input rock outcrop acceleration levels ranging from 0.044g to 0.220g. The resultant site-specific seismic responses indicated the amplified ground motions in the short-period range near the site period of Ssang-gye-sa. Furthermore, the intensity on rock outcrop of the 1936 Jirisan earthquake was estimated by making a comparison between the site responses analysis results in this study and the full-scaled seismic test of pagoda model in the prior study.

• Journal of Korean Society of Environmental Engineers
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• v.28 no.3
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• pp.240-248
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• 2006

In this study, a retrofitting BNR process that was modified for the economical applicability was proposed and evaluated in the pilot plant($50m^3/d$). At the same time the bacterial community structure was investigated in the pilot plant by using FISH(fluorescent in situ hybridization) method. Economically 16% of the initial construction cost for the proposed process(introduction of a biological nutrient removal process of $60,000m^3/d$ scale basis) was reduced due to the absence of a bioreactor. Water treatment efficiencies and maintenance facilities of the modified process were satisfied with the strengthened discharge permits in Korea throughout a long term pilot plant operating including a winter season. Bacterial populations in the pilot plant and in the control plant(A2/O process, B SIP(Sewage Treatment Plant)) were remained uniformly during the test period, but bacterial structure in the bioreactor was changed drastically. Proportions of ${\beta}$-proteobacteria group including soil bacteria which play a important role in wastewater treatment increased $25{\sim}607%$ in population.