• Korean Journal of Clinical Laboratory Science
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• v.49 no.3
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• pp.214-219
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• 2017

Coal workers' pneumoconiosis (CWP) and chronic obstructive pulmonary disease (COPD) are characterized as chronic inflammation of the lung in miners exposed to coal mine dust. The aim of the present study was to compare the levels of serum lactate dehydrogenase (LD) and C-reactive protein (CRP) as the inflammatory indices between subjects with CWP and those with CWP and COPD (CWP+COPD), among a total of 97 subjects (27 control, 40 CWP, and 30 CWP+COPD patients). The mean levels of serum LD (165.7 vs 184.6 U/L, p=0.016) and CRP (0.08 vs 0.15 mg/dL, p=0.002) in subjects with CWP were higher than those of in subjects without CWP. The mean level of serum CRP (0.10 vs 0.19 mg/dL, p=0.008) in subjects with COPD was higher than that in subjects without COPD. In an analysis of covariance adjusted by age, the mean level of serum CRP showed statistical significance among the study groups, control, CWP, and CWP+COPD (0.07 vs 0.13 vs 0.19 mg/dL, p=0.005); the mean level of serum CRP in the CWP+COPD group was significantly higher than that of the control group (p=0.001). The results suggest that a high level of CRP in the serum may be associated with CWP and COPD in retired coal miners.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.6
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• pp.825-831
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• 2012

The retrofitting of a thickening unit process is widely considered in municipal wastewater treatment plants in Korea to enhance the anaerobic digestion efficiency. The authors examined the effect of feed concentration (2-34.1 g VS/L) and feed to microorganism (F/M) ratio (0.50-1.35 g VS/g VS) on anaerobic batch digestion of sewage sludge. Methane yield over 90 mL $CH_4/g$ $VS_{feed}$ was found at a feed concentration in the range of 12-26 g VS/L and a F/M ratio below 0.6 g VS/g VS. A high F/M ratio decreased methane yield and rate with oragnic acid accumulation. As sudden increase of sewage sludge concentration prior to anaerobic digestion would jeopardize the digester performance due to the rasied F/M ratio, gradual increase of the sludge feed concentration or an additional biomass retention in the digester is recommended.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.3
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• pp.55-62
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• 2017

In this study, we investigated the effect of seaweed (SW) addition on the anaerobic digestion of food waste (FW). Anaerobic batch experiments were carried out at various substrate concentrations (2.5 to 10.0 g VS/L) and mixing ratios (FW:SW=100:0, 75:25, 50:50, 25:75 and 0:100 on VS basis) of FW and SW. The methane yield of FW alone was 394, 377, 276, $49mL\;CH_4/g\;VS_{added}$ at each substrate concentration (2.5 to 10.0 g VS/L). In cases of co-digestion, methane yield decreased (up to 15 %) with increasing mixing ratio of SW at low substrate concentration (2.5 to 5.0 g VS/L), while it increased (up to 240 %) at high substrate concentration (7.5 to 10.0 g VS/L). The synergistic effect was calculated based on the amount of methane generated from the single-feedstock digestion of FW and SW. The synergistic effect was not found at 2.5 and 5.0 g VS/L. However, the synergistic effect increased (up to 25% = synergistic increment/total methane production at 10.0 g VS/L, FW:SW=50:50) with increasing the ratio of seaweed at 7.5 and 10.0 g VS/L. At 10.0 g VS/L of FW alone, the accumulated amount of organic acids was 7,426 mg COD/L, which was decreased to 2,346 mg COD/L by seaweed (FW:SW=50:50) addition. The reason for the synergistic effect was to control the production rate of the organic acids by adding SW that has a relatively lower biodegradability compared to FW.

• Journal of the Korea Organic Resources Recycling Association
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• v.11 no.4
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• pp.97-104
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• 2003

Hydrogen fermentation of food waste and sewage sludge was performed in serum bottles under various volatile solids(VS) concentrations(0.5~5.0%) and mixing ratios of two substrates(0:100-100:0, VS basis). Full quadratic equations, optimal conditions, and 90% acceptable conditions for hydrogen production potential and rate were obtained using cumulative methane production data and response surface methodology. The specific hydrogen production potential of food waste was higher than that of sewage sludge. However, hydrogen production potential increased as sewage sludge composition increased up to 13~19% at all the VS concentrations. The maximum specific hydrogen production potential of 122.9 mL/g $carbohydrate_{added}-COD$ was found at the waste composition of 87:13(food waste:sewage sludge) and the VS concentration of 3.0%. The relationship between carbohydrate concentration, protein concentration, and hydrogen production potential indicated that enriched protein by adding sewage sludge might enhance hydrogen production potential. The maximum specific hydrogen production rate was 111.2 mL $H_2/g$ VSS/h. Food waste and sewage sludge were, therefore, considered as a suitable main substrate and a useful auxiliary substrate, respectively, for hydrogen production.

• Tuberculosis and Respiratory Diseases
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• v.50 no.2
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• pp.158-170
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• 2001

Background : Although an oxidants and antioxidants imbalance has been considered in the pathogenesis of chronic obstructive pulmonary disease (COPD), there is a paucity of reports focussing on the smoking-induced changes of oxidants and antioxidants in COPD. Method : The concentration of antioxidants (ascorbic acid, uric acid, retinol, and $\alpha$- & $\gamma$-tocopherol) was measured in the serum and induced sputum of 30 healthy controls and 34 stable COPD patients using high performance liquid chromatography (HPLC). The inhibition of lipid peroxidation as an index of antioxidant capacity was measured in the serum by a TBA assay. Results : The serum concentration of ascorbic acid, $\alpha$-tocopherol, and retinol were significantly lower in the patients with COPD than in healthy controls ($484.8{\pm}473.3$ vs $1497.8{\pm}819.2\;pmol/L$, $48.38{\pm}17.34$ vs $73.96{\pm}26.29\;pmol/L$, p<0.001, and $9.51{\pm}8.33$ vs $15.01{\pm}5.88\;pmol/L$, p<0.05, respectively, mean$\pm$SD). However, there were little differences in the ascorbic acid and uric acid concentrations in the induced sputum between the COPD patients and the controls. The induced sputum to serum ratio of ascorbic acid was significantly higher in COPD patients compared with healthy control (0.375 vs 0.085, p<0.05). In the normal controls, the serum ascorbic acid concentration was lower in smokers than in nonsmokers ($1073{\pm}536$ vs $1757{\pm}845\;pmol/L$, p<0.05), but the level was still higher than that of the COPD patients (p<0.05). The serum retinol levels were correlated with $FEV_1$ in COPD patients (r=0.58, p<0.05). The products of lipid peroxidation were increased in normal smokers and COPD compared with norma1 nonsmokers ($115.56{\pm}19.93$ vs $120.02{\pm}24.56$ vs $91.87{\pm}20.71\;{\mu}mol/{\mu}mol$ Pi of liposome, p<0.05). Conclusion : Cigarette smoking may induce the dep1etion of serum antioxidants and this depletion of antioxidants is suggested to play a role in the pathogenesis of COPD.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.1
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• pp.62-68
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• 2013

The effect of organic substance on its degradation rate in burial site was investigated using batch tests. Substrate were swine and cattle with the initial concentrations of 2, 4, 6, 8, and 10 g VS(volatile solids)/L, respectively. The highest methane production rates of swine and cattle were found at 2 g VS/L as 46.3 and 48.4 ml CH4/g VS.d, respectively. As substrate concentration increased, the methane production rate decreased. The inhibition constants were n and m that were estimated using nonlinear inhibition model. The values of n and m were inhibition constants of methane production rate and ultimate methane yield, respectively. The values of n and m were 4.9 and 0.6 on swine and 1.1 and 0.4 on cattle. The methane production rate was responded sensitively by increase and decrease of substrate concentration, whereas ultimate methane yield do not relatively. From a relation between n and m, inhibitory effect of substrate concentration was confirmed as uncompetitive inhibition.

• Korean Journal of Agricultural and Forest Meteorology
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• v.21 no.4
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• pp.269-276
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• 2019

A semi-greenhouse experiment with field grown soybean (Glycine max L. cv Deawon, Uram, Jinpong, Soyon, Pungsangnamul, and Haewon) was performed in 2018. The experiment was aimed to investigate individual impacts of drought stress on soybean characteristic and seed yield. The three treatments were used in non-water stress (Control) during the soybean growth season, vegetative stage stress (VS), and flowering period stress (FS). Leaf number, LAI, leaf nitrogen concentration, and leaf biomass were decreased by drought at R4. In our study, the number of pods was 33.6% and 40.5% lower, respectively, in control than in VS and FS. In 100 seed weight, was 16.1% and 10.1% lower, respectively, in control than in VS and FS at R8. As a result, seed yield was 39.8% and 45.1% lower, respectively, in control than in VS and FS. Depending on the drought period, Daewon and Haewon showed a large decrease in yield, while Soyon did not change. The results of this study showed that flower and beginning pod setting stage responded more sensitively to the drought period than vegetative stage. Overall, these results demonstrate soybean seed yield formation more sensitive the during the flowing and beginning pod setting stage. We conclude that adequate water supply for pod setting stage, guaranteeing a high seed yield.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.233-233
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• 2014

InGaZnO 박막트랜지스터(TFT)는 기존의 널리 사용되던 비정질 실리콘보다 높은 전하이동도와 Ion/off, 우수한 균일성과 신뢰성의 장점으로 최근 AMOLED양산에 적용되기 시작 하였다. 그러나 60인치 이상의 대면적 디스플레이와 초고해상도의 성능을 동시에 만족하기 위해 10 cm2/Vs정도의 전하이동도를 가지는 InGaZnO로는 한계가 있어 30 cm2/Vs 이상의 전하이동도를 가지는 물질의 연구가 필요하다. 연구에서는 높은 전하이동도를 만족하기 위해 InO2를, 우수한 신뢰성을 가지는 SnO2를 포함하는 InZnSnO로 실험을 진행하였다. 스퍼터링 시스템에서 ITO 타겟과 ZTO 타겟을 사용하여 동시증착법으로 채널을 증착하였고, 산소 분압 변화시에 IZTO TFT 소자 특성의 의존성을 평가하였다. Ar : O2=10 : 0 일 때와 Ar : O2=7 : 3 일 때의 이동도가 각각 12.6cm2/Vs, 19.7cm2/Vs로 산소 비율이 증가함에 따라 전하이동도가 증가하였다. 기존 IGZO 산화물 반도체에서는 산소 비율이 증가하면 산소공공(VO) 농도감소로 인해 전하이동도가 감소한다. 이는 전하농도가 증가하면 전하이동도가 증가하는 percolation 전도기구로 이해할 수 있다. 그러나 본 IZTO 물질에서는 산소비율 증가에 따라 오히려 전하이동도가 증가하였는데, 이는 IZTO 반도체에 함유된 Sn 이온의 가전자상태가 +2/+4가의 상대적 비율이 산소농도에 따라 의존하기 때문인 것으로 분석되었다.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.9 no.1
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• pp.14-22
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• 2006

Purpose: To identify factors that influence serum zinc concentrations in children with acute gastroenteritis. Methods: Thirty-two children under 5 years of age (15 boys and 17 girls) were selected randomly among those who visited to an pediatric emergency room of Ehwa Womans University Mokdong Hospital with acute gastroenteritis from May to August 2005. This study estimated the association between serum zinc concentrations and clinical, biochemical variables in patients with acute gastroenteritis. Results: Serum zinc concentration was lower in febrile patients than afebrile patients with acute gastroenteritis ($67.5{\pm}25.3$ vs $85.5{\pm}14.2$, p<0.05). It also was lower in patients with positive C-reactive protein (CRP) than those with negative CRP ($63.9{\pm}25.4$vs $86.7{\pm}13.8$, p<0.05). Serum zinc concentration was negatively correlated (r=-0.494, p<0.05) with CRP concentration, whereas positively correlated with hematocrit (r=0.370, p<0.05), total protein (r=0.474, p<0.05), and albumin (r=0.636, p<0.05). Twelve patients (37.5%) showed very low serum zinc concentration (< $70{\mu}g/dL$) without clinical symptoms of deficiency or growth retardation. Frequency of febrile illness or positive CRP is significantly greater in group with zinc < $70{\mu}g/dL$ than the group with zinc ${\geq}70{\mu}g/dL$ (91.7% vs 55%, p<0.05; 91.7% vs 40%, p<0.05, respectively). Conclusion: In patients with acute gastroenteritis, serum zinc concentration was influenced by various factors such as fever, CRP, and biochemical factors. For evaluating zinc status in the body. factors.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.10 no.2
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• pp.185-192
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• 2007

Purpose: This study was conducted to evaluate the role of adiponectin, leptin, and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) in the pathogenesis of non-alcoholic fatty liver disease (NAFLD) in obese children, and to elucidatethe relationship between these adipokines and insulin resistance. Methods: A total of 61 obese children (M : F=42 : 19, mean age 11.2${\pm}$1.3 years) admitted to our facility between March 2004 and June 2005 were included in this study. Patients were divided into three groups based on their NAFLD status obese children without fatty liver (N=23); obese children with simple steatosis (N=20); and obese children with non-alcoholic steatohepatitis (NASH) (N=18). The serum levels of adiponectin, leptin, and TNF-${\alpha}$ were measured, and insulin resistance determined by homeostasis model assessment (HOMA-IR) was calculated to estimate insulin resistance. In addition, the VSR (visceralsubcutaneous fat ratio) was estimated using abdominal computed tomography. Results: There was no difference in serum TNF-${\alpha}$ and leptin levels observed between the 3 groups (22.13${\pm}$6.37 vs. 21.35${\pm}$6.95 vs. 25.17${\pm}$9.30; p=0.342 & 20.29${\pm}$8.57 vs. 16.42${\pm}$6.85 vs. 20.10${\pm}$7.86; p=0.330). However, the serum adiponectin level was significantly lower in children with non-alcoholic steatohepatitis (NASH) than in the other two groups (6.08${\pm}$1.38 in children without steatosis vs. 5.69${\pm}$0.79 in simple steatosis vs. 4.93${\pm}$1.75 in NASH; p=0.026). In addition, the VSR was significantly increased in the NASH group (0.31${\pm}$0.08 vs. 0.32${\pm}$0.11 vs. 0.47${\pm}$0.14; p=0.001), and HOMA-IR revealed a significant difference among the three groups (4.77${\pm}$3.67 vs. 6.89${\pm}$7.05 vs. 10.42${\pm}$6.73; p=0.000). However, there was no significant correlation observed between the adiponectin levels and the HOMA-IR or the VSR (r=-0.117; p=0.450 & r=-0.106; p=0.499). Conclusion: Insulin resistance may affect the development of hepatic steatosis and steatohepatitis in children, and the results of this study suggest that, of several adipokines evaluated, adiponectin is important in the progression of steatosis to steatohepatitis in obese children.