• Korean Journal of Materials Research
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• v.19 no.1
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• pp.28-32
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• 2009

Silicon carbide (SiC) is a promising material for power device applications due to its wide band gap (3.26 eV for 4H-SiC), high critical electric field and excellent thermal conductivity. The Schottky barrier diode is the representative high-power device that is currently available commercially. A field plate edge-terminated 4H-SiC was fabricated using a lift-off process for opening the Schottky contacts. In this case, Ni/Ti dual-metal contacts were unintentionally formed at the edge of the Schottky contacts and resulted in the degradation of the electrical properties of the diodes. The breakdown voltage and Schottky barrier height (SBH, ${\Phi}_B$) was 107 V and 0.67 eV, respectively. To form homogeneous single-metal Ni/4H-SiC Schottky contacts, a deposition and etching method was employed, and the electrical properties of the diodes were improved. The modified SBDs showed enhanced electrical properties, as witnessed by a breakdown voltage of 635 V, a Schottky barrier height of ${\Phi}_B$=1.48 eV, an ideality factor of n=1.04 (close to one), a forward voltage drop of $V_F$=1.6 V, a specific on resistance of $R_{on}=2.1m{\Omega}-cm^2$ and a power loss of $P_L=79.6Wcm^{-2}$.

• Journal of Haehwa Medicine
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• v.16 no.2
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• pp.147-169
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• 2007

To evaluate the therapeutic effects of BGG on atopic dermatitis, we investigated the composition of immune cells of lymph node, PBMC and skin of Dermatophagoides farinae-induced NC/Nga mice. The levels of immunoglobulins in serum were analyzed at the protein level and the amount of pathologic cytokines were investigated using CD3/CD28 stimulated splenocytes. The results are summarized below; 1. BGG showed no cytotoxic effect up to $200\;{\mu}g/m{\ell}$ on mLFC in vitro. 2. BGG showed no hepatotoxicity in vivo based on the levels of ALT and AST. 3. Atopic dermatitis was improved through naked eye examination. BGG reduced the skin clinical index from 2.9 to 1.3 (p<0.01). 4. H&E and toluidine blue staining of tissue biopsies revealed that BGG inhibited the infiltration of lymphocytes and mast cells to skin. 5. BGG reduced the number of CD19 positive B cells in PBMCs by 16% (p<0.01), whereas cells were increased by 26% (p<0.05) in lymph nodes. 6. BGG reduced the numbers of B220+/CD23+ cells by 15% (p<0.01) and 33% in PBMCs and lymph node, respectively. 7. BGG reduced the numbers of B220+/IgE+ cells in PBMCs and lymph node by 21% and 33% (p<0.01), respectively. 8. BGG suppressed the levels of IgE (13%, p<0.001) as well as IgM (34%, p<0.001), IgG2a (40%, p<0.001) and IgG2b (26%, p<0.05). 9. BGG reduced the levels of IL-4 and IFN-$\gamma$ by 7% (p<0.05) and 13% (p<0.001) in anti-CD3 and anti-CD28-activated splenocytes, respectively. 10. BGG considerably inhibited the production of TNF-$\alpha$ and IL-6 by 42% (p<0.01) and 15% in the serum, respectively. Based on the results above, we concluded that BGG has therapeutic effects on atopic dermatitis by regulating the differentiation of B cells and isotype switching of IgE. Further investigations on the molecular mechanisms of BGG on atopic dermatitis are anticipated.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.4 no.1
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• pp.43-70
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• 1994

The effects of potassium chromate (500ppm/500ppm), potassium dichromate (500ppm/500ppm), cobalt chloride (100ppm/10ppm), methylmercuric chloride (100ppm/10ppm) on the biosynthesis of phospholipid and their composition of fatty acids in E.coli and B.subtilis were analyzed. The contents of phosphatidylethanolamine, phosphatidylcholine, phosphatidylinositol, phosphatidylglycerol, cardiolipin and total lipids in treatment with metal compounds were lower to compare with the control. The major fatty acid utilized for biosynthesis of phospholipid was palmitic acid in control of E.coli and B.subtilis. However, in treatment with metal compounds, changes of fatty acid composition utilized for phospholipid formation were as follows. In E.coli major fatty acids were palimitic acid (ave. 26.26%) and cis-vaccenic acid (ave. 10.94%) in treatment with potassium chromate, palmitic acid (ave. 31.41%/31.42%) and stearic acid (ave. 17.92%/19.41%) in treatment with potassium dichromate and cobalt chloride. And in treatment with raethylmercuric chloride, palmitic acid (ave. 26.66%), stearic acid (ave. 15.50%) and cis-vaccenic acid (ave. 20.59%) were used in phospholipid formation. In B.subtilis, the major fatty acid was palmitoleic acid (ave. 15.29% /10.22%) in treatment with potassium chromate and cobalt chloride, and stearic acid (ave. 16.01%) in treatment with potassium dichromate. On the other hand, cis-vaccenic acid (ave. 9.09%), palmitic acid (ave. 17.23%), stearic acid (ave. 6.66%), myristic acid (ave. 6.34%) and lauric acid (ave. 4.75%) were analyzed into major fatty acids in treatment with methylmercuric chloride. As shown in results, specific fatty acid pattern was came out in treatment with metal compounds according to bacteria and treatments.

• Journal of Preventive Medicine and Public Health
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• v.6 no.1
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• pp.87-99
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• 1973

The purpose of this project is offering fundamental and proper informations for the better health control and personnel management of the enlisted men of Marine corps in Korea. Survey has been done under 1,001 marine enlisted men for the purpose of understanding their condition of physique, vital capacity, and bodily strength. 1. Under the subject of physique, 7 items, body weight, chest-girth, relative body weight, relative chest-girth, Vervaeck index, and Roehrer index are listed, and under the subject of vital capacity, BTPS vital capacity and percent predicted vital capacity are listed, and under the subject of bodily strength, 7 items, grasping power, chinning-up, throwing a hanp-grenade, forward jumping, sitting-up, 100 meter sprinting, are listed. The total items are 16 and mean score of each one is as follow. 1)Physique : a. Height : $$168{\pm}0.15cm$$ b. Body weight : $$62.7{\pm}0.17kg$$ c. Chest-girth : $$91.4{\pm}0.16cm$$ d. Relative body weight : $$37.2{\pm}0.09$$ e. Relative chest-girth : $$54.3{\pm}0.10$$ f. Vervaeck index : $$91.6{\pm}0.15$$ g. Roehrer index : $$1.31{\pm}0.003$$ 2) Vital capacity : a. BTPS vital capacity : $$4470{\pm}20cc$$ b. % Predicted vital capacity : $$150{\pm}5.1%$$ 3) Bodily strength : a. Grasping power : $$41.4{\pm}0.26kg$$ b. Chinning-up : $$5.7{\pm}0.10$$ c. Throwing a hand-grenade : $$39.7{\pm}0.20m$$ d. Forward jumping : $$214{\pm}0.58cm$$ e. Sitting-up : $$19.1{\pm}0.25$$ f. Pushing-up : $$22.1{\pm}0.18$$ g. 100 meter sprinting : $$16.1{\pm}0.04sec$$. 2. Comparative analysis has been done about the conditional classes of marine enlisted men with the results of above mentioned 16 items. 7 classes according to the branches, 3 according to the ranks, 9 according to tile length of service are adopted respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.5
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• pp.577-583
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• 2012

This study investigated the antioxidant activities, and antimicrobial activity $in$ $vitro$ of an 80% ethanol extract from garlic, daikon, leek, ginger, onion, and green onion, which are widely-used ingredients in Korean food that contain sulfur. The total polyphenol content in ginger and leek extracts showed a high value ($233.63{\pm}4.59$ and $220.98{\pm}10.56$ mg/g GAE) and onions, leeks, garlic, and daikon followed by with $69.07{\pm}1.42$, $68.83{\pm}2.11$, $19.41{\pm}0.40$, $19.05{\pm}03.32$ mg/g GAE, respectively. DPPH radical scavenging activity was highest with ginger extracts ($1.57{\pm}0.15$ mg/mL as $IC_{50}$) followed in order of decreasing activity by leeks, onions, daikon, green onions, and garlic. The results of ABTS radical scavenging activity and FRAP value showed higher antioxidant activity in extracts from ginger and leek. The order of vegetables with most to least prevalent ABTS radical scavenging activity was green onions, onions, garlic, and finally daikon. From greatest to least FRAP value, the relevant vegetables were green onions, onions, daikon, and garlic (p<0.05). Ginger extracts showed promise against seven strains of microbes: $Bacillus$ $cereus$, $Bacillus$ $subtillis$, $Staphylococcus$ $aureus$, $Lactobacillus$ $plantarum$, $Escherichia$ $coli$, $Salmonella$ $enterica$, and $Pseudomonas$ $aeruginosa$. Garlic extracts (5 mg/disc) showed strong antimicrobial activity against $B.$ $cereus$ (22.3 mm) and $E.$ $coli$ (24.3 mm). Extracts of both onion and green onion showed antimicrobial activity against only $E.$ $coli$ (12.7 and 10.3 mm) and $B.$ $cereus$ (12.0 and 12.5 mm) at 10 mg/disc, and the inhibition zone diameter from extracts of garlic and leeks were 18.0 mm and 10.4 mm vs. $L.$ $plantarum$ at 10 mg/disc. This study showed positive antioxidant activities for ginger and leeks, and positive antimicrobial activities for leeks and garlic. These sulfur-containing vegetables are widely used in Korean food. Leeks especially could serve as a functional food preservative.

• Journal of Microbiology and Biotechnology
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• v.19 no.3
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• pp.257-264
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• 2009

A $\beta$-agarase gene, agaB34, was functionally cloned from the genomic DNA of a marine bacterium, Agarivorans albus YKW-34. The open reading frame of agaB34 consisted of 1,362 bp encoding 453 amino acids. The deduced amino acid sequence, consisting of a typical N-terminal signal peptide followed by a catalytic domain of glycoside hydrolase family 16 (GH-16) and a carbohydrate-binding module (CBM), showed 37-86% identity to those of agarases belonging to family GH-16. The recombinant enzyme (rAgaB34) with a molecular mass of 49 kDa was produced extracellularly using Escherichia coli $DH5{\alpha}$ as a host. The purified rAgaB34 was a $\beta$-agarase yielding neoagarotetraose (NA4) as the main product. It acted on neoagarohexaose to produce NA4 and neoagarobiose, but it could not further degrade NA4. The maximal activity of rAgaB34 was observed at $30^{\circ}C$ and pH 7.0. It was stable over pH 5.0-9.0 and at temperatures up to $50^{\circ}C$. Its specific activity and $k_{cat}/K_m$ value for agarose were 242 U/mg and $1.7{\times}10^6/sM$, respectively. The activity of rAgaB34 was not affected by metal ions commonly existing in seawater. It was resistant to chelating reagents (EDTA, EGTA), reducing reagents (DTT, $\beta$-mercaptoethanol), and denaturing reagents (SDS and urea). The E. coli cell harboring the pUC18-derived agarase expression vector was able to efficiently excrete agarase into the culture medium. Hence, this expression system might be used to express secretory proteins.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2875-2878
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• 2014

Background: Lung cancer is one of the commonest and most lethal cancers throughout the world. The majority of the patients present at advance stage and are not suitable for curative intent treatment. Even among patients with localized disease, there has been underutilization of curative treatment modalities. The aim of this study was to analyze the radical treatment utilization rates in patients with non small cell lung cancer (NSCLC) treated at our centre. Materials and Methods: We analyzed case records of 104 patients with a pathologically confirmed diagnosis of NSCLC having stage 1-3B disease who were treated at our centre over last 3 years, to assess the utilization of curative treatment modalities i.e. surgery or radical radiotherapy. Results: The median age of this cohort was 58 years. Out of 104 patients only 33 (31.7%) received curative intent treatment, 14 undergoing curative resection and 19 receiving radical doses of radiotherapy. The baseline characteristics of both the groups (with or without radical treatment) were not different. Major factors associated with underutilization with curative treatment were progressive disease or loss of follow up after chemotherapy and inappropriate use of TKI and/or palliative radiotherapy in patients with stage 1-3B disease. Patients who did not receive radical treatment had inferior PFS and OS than those who received radical treatment. Conclusions: In our practice we observed gross underutilization of curative intent treatment modalities in patients with NSCLCs which is associated with inferior survival.

• Childhood Kidney Diseases
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• v.19 no.2
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• pp.148-153
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• 2015

Purpose: We investigated trends in antibiotic resistance for gram-negative bacteria in infants with a urinary tract infection (UTI) over 15 years at a single institution. Methods: A retrospective chart review was conducted for children younger than 24 months who visited the emergency room and were diagnosed with a UTI between January 2000 and December 2014. We selected urine culture data that grew Escherichia coli and Klebsiella pneumoniae. Baseline clinical information and results of antimicrobial susceptibility tests were analyzed by dividing the 15-year study time frame into three periods (A: 2000-2004, B: 2005-2009, and C: 2010-2014). Results: During the study period, 478 applicable children were identified (E. coli, 89.7% and K. pneumoniae, 10.3%). Antibiotic resistance to third-generation cephalosporins was increased from period A to period C (A, 2.1%; B, 8.3%; C, 8.8%; P=0.025). Resistance to quinolones also showed a steady pattern during periods A to C, although it was not statistically significant (A, 7.9%; B, 9.7%; C, 12.4%; P=0.221). The incidence of Extended-spectrum ${\beta}$-lactamase (ESBL)-producing gram-negative bacteria increased from period A to period C (A, 1.4%; B, 7.6%; C, 8.2%; P=0.012). Conclusion: This study revealed that the common uropathogens E. coli and K. pneumoniae experienced increasing resistance rates against third-generation cephalosporins and a constant antibiotic resistance to quinolones in children younger than 24 months. We also showed a recent increased incidence of ESBL-producing gram-negative bacteria in patients with community-acquired UTIs. Therefore, it is necessary to actively surveil resistance in order to properly select empirical antibiotics.

• The Korean Journal of Community Living Science
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• v.20 no.1
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• pp.19-32
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• 2009

The purpose of this study was to examine household food insecurity and the associations of food insecurity with socioeconomic characteristics, food behaviors, health status and nutrient intake among elderly people in a rural area. This study included 191 elderly people (mean age = $72.0{\pm}7.4$) in Jeollabuk-do, Jangsu-gun. House food insecurity was measured using an adapted version of the USDA short form household food insecurity scale, and nutrient intake measured by a 24-hour dietary recall. Only 15.2% of the subjects were in food-insecure households, 84.8% of the elderly households were food-secure. The food-insecure households were significantly lower in the number of family, frequency of shopping, and perceived health status than the food-secure households. In addition, they had serious tooth problems and NSI (Nutrition Screening Index) scores. Food-insecure households were significantly lower in most areas of nutrient intake (energy, protein, fat, Ca, P, Fe, K, Na, Zn, Vit. $B_2$, niacin, Vit. E), and also lower in nutrient intake compared to dietary reference intake (energy, protein, P, Fe, K, Na, Vit. $B_1$, Vit. $B_2$, niacin, Vit. E). These results suggest that the household food insecurity measures used in this study were an important indicator of nutritional well-being among elderly persons in the rural area. Food insecurity should be considered an important issue to public health and food service programs should be expanded for food-insecure households in rural areas.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.12 no.10
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• pp.4378-4384
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• 2011

In order to evaluate the anti-oxidative capabilities of Angelica dahurica Radix ethanol extract (ADEE), we analyzed the contents of polyphenol and flavonoid compounds and the electron donating ability from ADEE. For animal experimentation, the test agent was topically applied to the artificial tanning spots which were induced by 1,500 mJ/$cm^2$ of ultraviolet B radiation on the backs of brown guinea pigs weighing approximately 450~500g. The test agent of $30{\mu}{\ell}$ was applied (6areas per group) twice a day, five days a week, for five weeks. On completion of the experiment, the animals were sacrificed under anesthetization, and the artificial tanning spots were obtained by biopsy punch and stained with H&E to observe the histological change in the epidermis and dermis. As a result, the contents of polyphenol and flavonoid compounds in ADEE were 20.7mg/g and 19.5mg/g respectively. As the for electron-donating capability of ADEE, it was observed that ADEE displays a dose-dependent antioxidative capacity of 14.8% and 19.8% at the concentration of 500 and 1000 ${\mu}g/m{\ell}$ respectively. Tissue staining with H&E revealed that the epidermis of the control group was slightly thicker than that of the other groups. However no inflammation or any other undesirable effect on the skin tissue due to ADEE was observed. These results indicate that ADEE is of value as a natural antioxidant.