• 한국재료학회지
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• 제19권1호
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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 $P_L=79.6Wcm^{-2}$.

• 혜화의학회지
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• 제16권2호
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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.

• 한국산업보건학회지
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• 제4권1호
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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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• 제6권1호
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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.

• 한국식품영양과학회지
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• 제41권5호
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• pp.577-583
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• 2012

본 연구는 황 함유 채소류 중 사용범위가 넓은 마늘, 무, 부추, 생강, 양파, 파를 80% 에탄올에 추출하여 항산화 및 항균효과에 대해 평가하였다. 추출 수율은 2.33~10.12%를 나타내었으며, 총 폴리페놀 함량은 생강이 $233.63{\pm}4.59$, 부추가 $220.98{\pm}10.56$ mg/g GAE로 높은 함량을 나타내었고, 양파, 파, 마늘, 무 순으로 $69.07{\pm}1.42$, $68.83{\pm}2.11$, $19.41{\pm}0.40$, $19.05{\pm}03.32$ mg/g GAE의 함량을 나타내었다. DPPH radical 소거활성을 측정한 결과, 생강의 $IC_{50}$ 값이 $1.57{\pm}0.15$ mg/mL로 가장 높았으며, 이어 부추>양파>무>파>마늘의 순이었다. ABTS 라디칼 소거활성 및 FRAP value의 측정 결과 역시 생강 및 부추 추출물에서 높은 항산화활성을 나타내었으며 ABTS 라디칼 소거활성의 경우 파>양파>마늘>무, FRAP value의 경우 파>양파>무>마늘의 순으로 항산화 활성을 나타내었다. 항산화 활성 측정결과 전체적으로 생강에서 가장 높은 항산화활성을 나타내었다. 항균활성 측정결과, 부추의 경우 실험에 사용된 7가지 균주에 대해 모두 항균 활성을 가지고 있는 것으로 나타났으며, 마늘의 경우(5 mg/disc), $B.$ $cereus$(22.3 mm) 및 $E.$ $coli$(24.3 mm)에 대해 높은 항균활성을 나타내었다. 양파와 파는 10 mg/disc 농도에서 $E.$ $coli$(12.7 및 10.3 mm)와 $B.$ $cereus$(12.0 및 12.5 mm) 균주에 대해서만 항균력을 나타내었고, $L.$ $plantarum$ 균주(10 mg/disc)에 대해서는 마늘(18.0 mm)과 부추(10.4 mm)가 항균활성을 나타내었다. 본 연구결과, 다양한 한국음식에 광범위하게 이용되는 황 함유채소류 중 생강 및 부추는 항산화 활성이, 부추 및 마늘은 항균력이 높아 특히 부추의 경우 식품 첨가물 및 식품 보존제로서도 활용될 수 있을 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제19권3호
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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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• 제15권6호
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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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• 제19권2호
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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.

• 한국지역사회생활과학회지
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• 제20권1호
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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.

• 혜화의학회지
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• 제18권2호
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• pp.47-62
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• 2009

Atopic dermatitis induced NC/Nga mice were used to investigate the efficacy of HYT on the recovery of dermatitic symptoms by how HYT influenced the immune related factors. The results are as below: 1. Compared to the control, HYT treated group showed recovery of atopic dermatitis by the naked eye observation, and significant reduction of dermatits index was observed after 14 weeks. 2. HYT treated group showed significant decrease of the ratio of CCR3+, B220+/IgE+, and Gr-1+/CD11b+ immune cells in dorsal skin by 40.5%, 34.2%, and 48.1%, respectively. 3. HYT treated group showed increase in the ratio of CD19+ immune cells within PBMC by 10.8%, as well as decrease in CD3+, CD3+/CD69+, NKT+ ratios by 5.3%, 35.2%, and 44.9%, respectively. 4. HYT treated group showed increase in the expression of IFN-$\gamma$ in serum by 589.3%, whereas the expression of IL-4, IL-5, IL-6, IL-13, TNF-$\alpha$, MCP-1 and RANTES were decreased by 31.4%, 82.1%, 97.1%, 39.5%, 83.7%, 26.1%, 48.6%, respectively. A 47.2% decrease in IgE expression was also observed. The results above strongly supported the improvement of atopic dermatitis by HYT treatment through immune modulation. Further studies on the synergistic effect of each ingredients of HYT and therapeutic effects according to the dosage of each ingredient should be followed for clinical applications. This work was (partly) supported by the RIC program of MKE(Ministry of Knowledge Economy) in Daejeon University.