• 환경위생공학
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• 제12권3호
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• pp.31-39
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• 1997

The seasonal and spatial changes in dissolved organic carbon(DOC) in Lake Kasumigaura, a shallow and eutrophic lake, were analyzed from October 1992 to October 1995. The proportion of T-DOC was classified by labile(L-DOC) and refractory DOC(R-DOC) on the basis of long-term incubation, fractionated the molecular weight of T-DOC by ultrafiltration. The porewater DOC were measured at sedimental surface of the central basin in order to evaluate the DOC released from the sediment. The proportion of L-DOC and R-DOC were accounted for about 15% and 85% of T-DOC in the central basin, respectively. The molecular weight(MW) distribution occupied some 60% of the low and medium MW. The horizontal variation of T-DOC concentrations trended to higher in the central basin than in the inlet of influent rivers, because of contribution by autochthonous organic carbon loading. The seasonal variation of T-DOC showed to higher summer than winter in the inlet of influent, but at the central basin it fluctuated little seasonally. During the high increase of porewater DOC in 1994 evaluated the high release possibility from the sediment surface (10cm). The present study suggests that autochthonous organic carbon loading must be controlled for improving the water quality of the eutrophic lakes.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 1999년도 임시총회 및 가을 학술발표회 초록집 The Korean Environmental Sciences Society
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• pp.27-30
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• 1999

• 한국관개배수논문집
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• 제10권2호
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• pp.147-152
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• 2003

• Environmental Engineering Research
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• 제7권2호
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• pp.93-101
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• 2002

The seasonal patterns of dissolved organic matter (DOM) in Lake Kasumigaura, a shallow, eutrophic lake, and serveral DOM sources in its catchment area were investigated. DOM was fractionated using three resin adsorbents into classes: aquatic humic substances (AHS=humic acid+fulvic acid), hydrophobic neutrals (HoN), hydrophilic acids (HiA), bases (BaS) and hydrophilic neutrals (HiN). The DOM produced significantly different fraction distributions depending on the origin of sample. AHS and HiA prevailed over AHS in the lake while AHS and HiA existed at almost the same concentration levels in the rivers. AHS seems to be a more dominant component in rever water than lake water. The dominance of organic acids was also observed in the DOM sources: forest stream (FS), plowed field percolate (PFP), domestic sewage (DS) and sewage treatment plant effluent (STPE).

• 생태와환경
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• 제36권3호통권104호
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• pp.304-310
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• 2003

수심이 얕고 부영양 호소인 L. Kasumigaura를 대상으로 퇴적층으로부터 유기물 용출특성을 조사하였다. 퇴적물의 함수율은 약 80%이상을 차지하고 있었으며 공극수의 DOC농도는 표층에서 높고 깊어질수록 감소하는 경향을 나타냈다. 특히 조사기간중 공극수의 DOC농도(104mg C/l)가 크게 증가하여 공극수로부터 수체로 용출 가능성이 높을 것으로 추정되었다. DOC 용출실험결과, 호기조건에서는 Labile-DOC (L-DOC)용출이 거의 관측되지 않았고 Refractory-DOC (R-DOC)만 관측되었으며, 혐기조건에서는 L-DOC와 R-DOC 모두 용출되는 것으로 나타났다. 이러한 결과는 퇴적층의 상부수층에 DO가 충분히 유지되면 L-DOC는 용출되어도 호기성 bacteria에 의해 쉽게 분해되기 매문에 R-DOC만 용출되는 것으로 조사되었으며, 혐기조건하에서는 혐기성 bacteria의 유기물 분해능력의 감소로 L-DOC와 R-DOC모두 용출되는 것으로 나타났다. 결과적으로 내부생성기원의 유기물중 퇴적층으로부터 R-DOC 용출은 수체의 유기물 농도를 증가시키는 주요 원인으로 나타났으며, 수중 유기물의 대부분을 차지하고 있는 R-DOC는 유기물순환에 중요한 역할을 담당하고 있다는 사실이 확인되었다.

• 한국해양학회지
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• 제24권3호
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• pp.148-156
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• 1989

본 연구는 여러 수생생태계에서 유기물의 동적순환에 따른 부유성 박테리아와 부착성 박테리아의 그램염색(gram-stain) 특성을 알아보기 위한 일련의 시도로서 일본에서 두번째로 크며 부영양화가 상당히 진전된 가스미가우라 호수에서 1년간, 매주 실시했다. 이 전형적인 부영양형(eutrophic) 수생생태계의 박테리아군집의 그램염색 특성은 중영양형(mesotrophic) 환경과 같이 유기물의 유입에 따라 변화함을 보여준다. 그램음성(negative) 박테리아군집은 부유성 박테리아군집이 약 57%, 부착성 박테리아군집이 약 53%이며, 두 군집의 통계분석은 서로 다른 특성을 보여준다. 부착성 박테리아군집은 그램 양성, 음성 모두 쇄설성 유기물 형성과 분해에 영향을 미친다. 또한 그램 음성 부유박테리아는 특히 용존 유기물의 동적순환에 관여한다.

• 한국수자원학회:학술대회논문집
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• 한국수자원학회 1987년도 제29회 수공학연구발표회논문초록집
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• pp.113-122
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• 1987

A numerical simulation technique of three-dimensional finite difference model is developed to study the groundwater flow system in Dcjima, an upland area which faces Kasumigaura Lake. For general perspectives of the groundwater flow system, a steady state three-dimentional model is simulated. For the sedimentary mud formations which are found in the representative formation, three situations of hydraulic conductivity are considered, representing an isotropic condition and situations where the horizontal permeability is equal to 10 times and 100times of the vertical one. The finite difference grid used in the simulation has 60x50x30=90,000 nodes. A converged solution with a tolerance of 0.001 meter of hydraulic head is set. Having determined the flow net by using a steady state three-dimensional model. the results for the three cases of hydraulic conductivity are compared with the results of tracer methods (Bae and Kayane 1987) With the aid of four representative vertical cross-sections, groundwater flow systems in the study area are assumed. Water balances for the three cases indicate very good agreement between total recharge and discharge in each case Analyses of groundwater flow system based on the tritium concentrations and water quality measurements (Bae and Kayane 1987) are confirmed by the numerical simulation and the results obtained by these two methods appeared to be in close agreement.

• The Korean Journal of Pain
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• 제31권1호
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• pp.10-15
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• 2018

Background: To identify a new strategy for postoperative pain management, we investigated the analgesic effects of allopregnanolone (Allo) in an incisional pain model, and also assessed its effects on the activities of the primary afferent fibers at the dorsal horn. Methods: In experiment 1, 45 rats were assigned to Control, Allo small-dose (0.16 mg/kg), and Allo large-dose (1.6 mg/kg) groups (n = 15 in each). The weight bearing and mechanical withdrawal thresholds of the hind limb were measured before and at 2, 24, 48, and 168 h after Brennan's surgery. In experiment 2, 16 rats were assigned to Control and Allo (0.16 mg/kg) groups (n = 8 in each). The degree of spontaneous pain was measured using the grimace scale after the surgery. Activities of the primary afferent fibers in the spinal cord (L6) were evaluated using immunohistochemical staining. Results: In experiment 1, the withdrawal threshold of the Allo small-dose group was significantly higher than that of the Control group at 2 h after surgery. Intergroup differences in weight bearing were not significant. In experiment 2, intergroup differences in the grimace scale scores were not significant. Substance P release in the Allo (0.16 mg/kg) group was significantly lower than that in the Control group. Conclusions: Systemic administration of Allo inhibited mechanical allodynia and activities of the primary afferent fibers at the dorsal horn in a rat postoperative pain model. Allo was proposed as a candidate for postoperative pain management.

• 물과 미래
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• 제22권1호
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• pp.81-90
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• 1989

호수와 접하고 있는 홍적대지의 지하수류동계를 알기 위하여 삼차유한차분모형을 개발하여 삼차원정상모의 발생을 행하였다. 대표지층속에 점토층이 렌즈상으로 포함되어 있어 세가지 경우의 이방성을 고려하였다. 모의 발생에는 60$\times$50$\times$30=90,000의 격자점을 설정하였으며 수속판정체계는 0.001m로 하였다. 세가지 경우의 이방성에 대하여, 삼차원정상모의 발생을 행하여 얻어진 결과로부터 해석된 지하수류동계와 추적자 및 수질에 의한 해석(배.비근, 1987)의 결과를 비교하였다. 삼차원해석에서 얻어진 네 개의 대표적인 연직2차원 등 포텐샬단면으로부터 연구지역의 지하수류동계를 추정하였으며 그 결과는 유역산출율과 지하수의 함량-유출량 분포로부터 추정되는 결과와 다름이 없었다.

• Asian Pacific Journal of Cancer Prevention
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• 제15권16호
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• pp.6571-6574
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• 2014

Background: Alcohol is well established as a risk factor for cancer development in many organ sites. To assess the reliability and validity of the Alcohol Use Disorders Identification Test - Consumption (AUDIT-C) for detecting alcohol use disorders or risky drinking in Japanese adults the present study was conducted. Materials and Methods: A test-retest method was applied with a 2-week interval with 113 health care employees. The k coefficient, Cronbach's coefficient alpha, Spearman's correlation coefficient, and intraclass correlation coefficient (ICC) were determined and the validity of the AUDIT-C was analyzed using the data from a nationwide survey on adult alcohol use conducted in 2008 (n=4,123). Results: The reliability of the AUDIT-C score was high (${\kappa}$ coefficient=0.63, Cronbach's alpha=0.98, correlation coefficient=0.95, and ICC=0.95). According to the likelihood ratio and Youden index, appropriate cutoffs for the AUDIT-C were ${\geq}5points$ in men and ${\geq}4$ points in women. The sensitivity and specificity of these cutoffs for identifying ${\geq}8$ points on the AUDIT were 0.88 and 0.80, respectively, for men (positive likelihood ratio [LR+]=4.5) and 0.96 and 0.87, respectively, for women (LR+=7.7). The sensitivity and specificity of the cutoffs for identifying ${\geq}12$ points on the AUDIT were 0.90 and 0.84, respectively, for men (LR+=5.8) and 0.93 and 0.94, respectively, for women (LR+=15.8). The sensitivity and specificity of the cutoffs for identifying ${\geq}16$ points on the AUDIT were 0.93 and 0.80, respectively, for men (LR+=4.7) and 0.92 and 0.98, respectively, for women (LR+=55.6). With higher scores on the AUDIT, the specificity decreased and false-positives increased. The appropriate cutoffs for identifying risky drinking were the same for both genders. Conclusions: The reliability and validity of the AUDIT-C are high, indicating that it is useful for identifying alcohol use disorders or risky drinking among the general population in Japan, a group at high risk of cancer development.