• Title/Summary/Keyword: Kwon Young

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Monitoring of Methicillin Resistant Staphylococcus aureus from Medical Environment in Korea. (국내 의료 환경 중의 Methicillin 내성 Staphylococcus aureus의 모니터링에 관한 연구)

  • Kwon, Young-Il;Kim, Tae-Woon;Kim, Hae-Yeong;Chang, Yun-Hee;Kwak, Hyo-Sun;Woo, Gun-Jo;Chung, Yun-Hee
    • Microbiology and Biotechnology Letters
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    • v.35 no.2
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    • pp.158-162
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    • 2007
  • Methicillin-resistant Staphylococcus aureus (MRSA) is one of a major nosocomial pathogen worldwide and the emergence of this strain has become a major clinical problem. This study was performed for 13 hospitals with more than 400 beds in the country by collecting samples including hands and nasal cavities of doctors, nurses, guardians and patients. Also, additional 320 samples of hands and nasal cavities of 160 community resident in different locations and regions were collected. In all of medical environments and community resident, 625 strains of S. aureus were detected. Among 625 strains of S. aureus, 585 strains(93.6%) showed the resistance to at least one kind of antimicrobial and 112 strains (17.9%) showed multi-drug resistance with the resistance to 4 different types of antimicrobial. Total 152 MRSA strains (24.3%) were isolated from medical environment and community resident. In nasal cavity and hand, 49 MRSA (19.4%) and 103 (27.6%) MRSA were isolated, respectively Minimum inhibitory concentration(MIC) test is used to measure for susceptibility of MRSA isolated to oxacillin. At a concentration $16{\mu}g/ml$ of oxacillin, 11 strains were inhibited. 32 strains at $32{\mu}g/ml$, 41 strains at $64{\mu}g/ml$, 3 strains at $128{\mu}g/ml$, 25 stains at $256{\mu}g/ml$ and 40 strains at over $256{\mu}g/ml$ were inhibited. It was considered that medical environment showed higher than livestock and marine environments in MRSA detection rate.

A Comparison Study of Aerosol Samplers for PM10 Mass Concentration Measurement (PM10 질량농도 측정을 위한 시료채취기의 비교 연구)

  • Park, Ju-Myon;Koo, Ja-Kon;Jeong, Tae-Young;Kwon, Dong-Myung;Yoo, Jong-Ik;Seo, Yong-Chil
    • Journal of Korean Society of Environmental Engineers
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    • v.31 no.2
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    • pp.153-160
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    • 2009
  • A PM10 (aerodynamic diameter${\leq}$10 ${\mu}m$) sampler is used to quantify the potential human exposure to suspended particulate matter (PM) and to comply with the governmental regulation. This study was conducted to compare and evaluate the same PM10 cutpoint and different slopes between United States Environmental Protection Agency (USEPA) PM10 sampling criterion and American Conference of Governmental Industrial Hygienists/$Comit\acute{e}$ $Europ\acute{e}en$ de Normalization/International Organization for Standardization thoracic PM10 sampling criterion through theory and experiment. Four PM10 samplers according to the USEPA criterion and one RespiCon sampler in accordance with the thoracic PM10 criterion were used in the present study. In addition, one DustTrak monitor was used to measure real time PM10 mass concentrations. All six aerosol samplers were tested in a PM generation chamber using polydisperse fly ash. Theoretical mass concentrations were calculated by applying the measured particle size distribution characteristics (geometric mean = 6.6 ${\mu}m$, geometric standard deviation = 1.9) of fly ash to each sampling criterion. The measured mass concentrations through a chamber experiment were consistent with theoretical mass concentrations in that a RespiCon sampler with the thoracic PM10 criterion collected less PM than a PM10 sampler with the USEPA criterion. The overall chamber experiment results indicated, when a PM10 sampler was used as a reference sampler, that (1) a RespiCon sampler had a normalizing factor of 1.6, meaning that this sampler underestimated an average 60% of PM10 mass sampled from a PM10 sampler, and (2) a DustTrak real-time monitor using a PM10 inlet had a calibration factor of 2.1.

Polymerization of dual cured composites by different thickness (두께에 따른 이중 중합형 복합레진의 중합)

  • Kim, Yun-Ju;Jin, Myoung-Uk;Kim, Sung-Kyo;Kwon, Tae-Yub;Kim, Young-Kyung
    • Restorative Dentistry and Endodontics
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    • v.33 no.3
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    • pp.169-176
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    • 2008
  • The purpose of this study was to evaluate the effect of thickness, filling methods and curing methods on the polymerization of dual cured core materials by means of microhardness test. Two dual cured core materials, MultiCore Flow (Ivoclar Vivadent AG, Schaan, Liechtenstein) and Bis-Core (Bisco Inc., Schaumburg, IL, USA) were used in this study. 2 mm (bulky filled), 4 mm (bulky filled), 6 mm (bulky and incrementally filled) and 8 mm (bulky and incrementally filled)-thickness specimens were prepared with light cure or self cure mode. After storage at $37{\circ}C$ for 24 hours, the Knoop hardness values (KHN) of top and bottom surfaces were measured and the microhardness ratio of top and bottom surfaces was calculated. The data were analyzed using one-way ANOVA and Scheffe multiple comparison test, with ${\alpha}$= 0.05. The effect of thickness on the polymerization of dual cured composites showed material specific results. In 2, 4 and 6 mm groups, the KHN of two materials were not affected by thickness. However, in 8 mm group of MultiCore Flow, the KHN of the bottom surface was lower than those of other groups (p < 0.05). The effect of filling methods on the polymerization of dual cured composites was different by their thickness or materials. In 6 mm thickness, there was no significant difference between bulk and incremental filling groups. In 8 mm thickness, Bis-Core showed no significant difference between groups. However, in MultiCore Flow, the microhardness ratio of bulk filling group was lower than that of incremental filling group (p < 0.05). The effect of curing methods on the polymerization of dual cured composites showed material specific results. In Bis-Core, the KHN of dual cured group were higher than those of self cured group at both surfaces (p < 0.05). However, in MultiCore Flow, the results were not similar at both surfaces. At the top surface, dual cured group showed higher KHN than that of self cured group (p < 0.05). However, in the bottom surface, dual cured group showed lower value than that of self cured group (p < 0.05).

Studies on the Separation and Discrimination of the Natural Yellow Pigment on Croaker (참조기 천연색소의 분리 및 판별법에 관한 연구)

  • Kim, Hee-Yun;Hong, Ki-Hyung;Hong, Jin-Hwan;Kim, Dong-Sul;Han, Sang-Bae;Lee, Eun-Ju;Lee, Jeung-Seung;Kang, Kil-Jin;Chung, Hyung-Wook;Song, Kyung-Hee;Park, Jong-Seok;Kwon, Yong-Kwan;Jang, Young-Mi;Shin, Il-Shik;Lee, Chang-Kook;Park, Hee-Yul;Ha, Sang-Chul;Jo, Jae-Sun;Park, Hye-Kyung
    • Korean Journal of Food Science and Technology
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    • v.34 no.5
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    • pp.762-769
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    • 2002
  • As a preliminary test for defining intact yellow croaker pigment, the pigment was analyzed by column chromatography and UV-vis spectrophotometry. All maximum absorbance wavelengths commonly showed three maximum absorbance ranges, similar to those of carotenoid, suggesting that the tested pigment may be carotenoid. We detected total six peak RT values in the chromatogram through PDA-HPLC under gradient mode (behavior A at 10% for initial 2 min and changed to behavior B for 60 min). Most pigments were detected at the peak with 3.27 RT value. Because seven peaks were detected under gradient mode and three under isocratic mode [methanol : methylene chloride (90 : 10, v/v)], gradient mode was determined to be more appropriate for quantitative analysis. By the comparison test of RT values among yellow pigment in croakers and reference pigments, such as zeaxanthine, ${\beta}-cryptoxanthine$, ${\beta}-carotene$, and astaxanthin, only ${\beta}-cryptoxanthine$ was detected in the white croaker, whereas such pigment of yellow croaker having RT value of 31.02 was not detected. Therefore, RT value was found to be applicable for detecting adulterated croaker.

The Effect of Isoflavone Supplementation on Bone Metabolism in Ovariectomized SD Rats (이소플라본 보충이 난소절제 흰쥐의 골대사에 미치는 영향)

  • Park, Young-Hee;Yoon, Sun;Chung, Soo-Youn;Yang, Seoung-Oh;Yoo, Tae-Moo;Yang, Ji-Sun;Kwon, Dae-Joong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.4
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    • pp.657-661
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    • 2001
  • Osteoporosis that is associated with ovarian hormone deficiency following menopause (postmenopausal osteoporosis) is by far the most common cause of age-related bone loss. Isoflavone has been reported as a natural substance that possibly minimizes bone loss in postmenopausal women. This study was conducted to investigate the preventing, treating effects of isoflavone on bone loss in ovariectomized rats. 120 Sprague Dawley rats of 13 week-old were devided into 2 groups, a treatment group and prevention group. Each group was consisted of six subgroups; control (CON), sham operated (SH) or ovariectomized (OVX) and isoflavone supplemented goups: OVX+0.25mg isoflavone/kg diet (OL), OVX+0.8mg isoflavone/kg diet(OM) and OVX+2.5mg isoflavone/kg diet(OH). to study the preventing effects of isoflavone on bone loss, OL, OM and OH groups were fed with isoflavone from 4 days after ovariectomization. Treating effects of isoflavone on bone metabolism were investigated with OL, OM, OH groups supplemented with isoflavone from 8 weeks after ovariectomization. Isoflavone supplementation continued for 8 weeks. At 8 weeks after ovariectomization significant increase in alkaline phosphatase occurred comparing with CON and SH group. By isoflavone supplementation from 4 days after ovariectomy alkaline phosphatase and urinary hydroxyproline were lowered and bone mineral density, bone strength of the femur and tibia and bone dry weight were slightly enhanced with no significant difference. Isoflavone supplemented group at the level of 0.8mg/kg diet (OM group) had significantly lower serum alkaline phosphatase, urinary hydroxyproline, and higher strength of femur than OVX group. Groups with isoflavone supplementation fro 8 weeks after ovariectomy had lower level of serum alkaline phosphatase, urinary hydroxyproline than OVX group. Bone mineral density, bone dry weight and bone strength of the femur and tibia were slightly enhanced by isoflavone supplementation. However there was no significanct difference between OVS ad isoflavone supplementation groups. The results suggest that isoflavone might have potential role for preventing postmenopausal bone loss. Isoflavone supplementation at early stage of postemenopause may be beneficial to age-related bone health.

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Study on the Intake Pattern of Health Intended Foods Depending on Inclusion of Proclaimed Health Functional Food Materials (건강기능식품에 의해 고시된 원료 포함여부에 따른 건강증진용 식품의 섭취양상 비교)

  • Park, You-Gyoung;Park, Mi-Young;Sung, Mi-Kyung;Kwon, Hoonjeong
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.34 no.3
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    • pp.374-379
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    • 2005
  • The intake of health foods with physiological effects may cause adverse effects due to their intrinsic compounds, external contamination or consumers' eating patterns. To keep pace with the increasing interest on the safety assurance, Health Functional Food Act has been enacted and standards and specifications for 32 products have been proclaimed by Korea Food and Drug Administration in 2004. To reduce the safety problems related with the intake of non regulated health intended food, we classified the health intended foods materials into two groups, as proclaimed health functional food materials and others, and examined the difference of intake patterns on both categories. Among 16,474 health intended foods responded by 5,175 respondents and their household members, 49.2% were categorized as health functional food materials. The average number of total health intended foods intake and health functional foods intake per person were 3.19 and 1.58 respectively. The proportion of health functional foods in total health intended foods per person was higher in the group with less than 20 years old, therefore this age group needs relatively low concern. On the other hand, 40-59 years old females who have taken the highest number of health food items, 30-59 years old males who had the lowest proportion of health functional foods to total health intended food, and their consumed foods such as medicinal plant and animal protein based restoratives need relatively high concern about intake safety of health foods.

Study on the Antioxidative Activities and Anti-Inflammatory Effect of Kaempferol and Kaempferol Rhamnosides (Kaempferol 및 Kaempferol Rhamnosides의 항산화 활성 및 항염 효과에 관한 연구)

  • Lee, Keun-Ha;Cho, Young-Long;Joo, Chul-Gue;Joo, Yeon-Jeong;Kwon, Sun-Sang;Ahn, Soo-Mi;Oh, Su-Jin;Rho, Ho-Sik;Park, Chung
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.37 no.3
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    • pp.257-264
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    • 2011
  • In this study, to evaluate the antioxidative activities and anti-inflammatory effects of kaempferol and its rhamnosides, we performed the free radical scavenging assay, ROS inhibition assay and TARC (thymus and activation-regulated chemokine) assay. Also, we studied physiological activity of kaempferol and its rhamnosides (${\alpha}$-rhamnoisorobin, afzelin, kaempferitn) by structure-activity relations. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities were determined with kaempferol (62.5 ${\mu}M$) and ${\alpha}$-rhamnoisorobin (50.0 ${\mu}M$) but afzelin and kaempferitrin did not show free radical scavenging activities. Kaempferol showed a 97.5, 57.8, 47.8 % inhibition of ROS (reactive oxygen species) generated at concentrations of 10, 50 and 100 ${\mu}M$, compared to control (100 %). ${\alpha}$-rhamnoisorobin showed a 93.1, 59.1 and 41.4 % inhibition of ROS at the same concentration. We investigated the inhibitory effects of kaempferol and its rhamnosides on TARC expression. Kaempferol showed a 48.8, 5.5 and 4.4 % inhibition of TARC generated at 10, 50 and 100 ${\mu}M$, compared to control. ${\alpha}$-Rhamnoisorobin showed a 88.1, 19.0 and 1.0 % inhibition of TARC generated at the same concentration. In conclusion, these results indicate that kaempferol and ${\alpha}$-rhamnoisorobin have good antioxidative activities and anti-inflammatory effects that could be applicable to new functional cosmetics for anti-aging and anti-inflammation.

Electrochemical Characterization of Anti-Corrosion Film Coated Metal Conditioner Surfaces for Tungsten CMP Applications (텅스텐 화학적-기계적 연마 공정에서 부식방지막이 증착된 금속 컨디셔너 표면의 전기화학적 특성평가)

  • Cho, Byoung-Jun;Kwon, Tae-Young;Kim, Hyuk-Min;Venkatesh, Prasanna;Park, Moon-Seok;Park, Jin-Goo
    • Journal of the Microelectronics and Packaging Society
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    • v.19 no.1
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    • pp.61-66
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    • 2012
  • Chemical Mechanical Planarization (CMP) is a polishing process used in the microelectronic fabrication industries to achieve a globally planar wafer surface for the manufacturing of integrated circuits. Pad conditioning plays an important role in the CMP process to maintain a material removal rate (MRR) and its uniformity. For metal CMP process, highly acidic slurry containing strong oxidizer is being used. It would affect the conditioner surface which normally made of metal such as Nickel and its alloy. If conditioner surface is corroded, diamonds on the conditioner surface would be fallen out from the surface. Because of this phenomenon, not only life time of conditioners is decreased, but also more scratches are generated. To protect the conditioners from corrosion, thin organic film deposition on the metal surface is suggested without requiring current conditioner manufacturing process. To prepare the anti-corrosion film on metal conditioner surface, vapor SAM (self-assembled monolayer) and FC (Fluorocarbon) -CVD (SRN-504, Sorona, Korea) films were prepared on both nickel and nickel alloy surfaces. Vapor SAM method was used for SAM deposition using both Dodecanethiol (DT) and Perfluoroctyltrichloro silane (FOTS). FC films were prepared in different thickness of 10 nm, 50 nm and 100 nm on conditioner surfaces. Electrochemical analysis such as potentiodynamic polarization and impedance, and contact angle measurements were carried out to evaluate the coating characteristics. Impedance data was analyzed by an electrical equivalent circuit model. The observed contact angle is higher than 90o after thin film deposition, which confirms that the coatings deposited on the surfaces are densely packed. The results of potentiodynamic polarization and the impedance show that modified surfaces have better performance than bare metal surfaces which could be applied to increase the life time and reliability of conditioner during W CMP.

Home Range Size and Habitat Environment Related to the Parturition of Roe Deer at Warm-Temperate Forest in Jeju Island Using GPS-CDMA Based Wildlife Tracking System (GPS와 CDMA를 이용한 난대림의 출산 전후 암노루 행동권 및 서식환경 조사)

  • Kim, Eun-Mi;Kwon, Jin-O;Kang, Chang-Wan;Song, Kuk-Man;Min, Dong-Won
    • Journal of the Korean Association of Geographic Information Studies
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    • v.16 no.2
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    • pp.65-74
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    • 2013
  • A research program for the roe deer (Capreolus pygargus) has been set up at the Jeju Experimental Forest of Warm-temperate and Subtropical Forest Research Center in Jeju Island. To explore the home range size and habitat environment, 3 males and 3 females have been captured and released with GPS-CDMA based telemetry since 24th April 2012. Among them 2 females were captured at Hannam Forest of Seoguipo, were pregnant and monitored by the tracking system. There are significantly different patterns in behavior around the parturition. After parturition they show recurrence behavior toward one point in the forest, while they have irregular patterns in moving before. To calculate the home range size, the MCP (minimum convex polygon) and Kernel Method are applied through the extension of ESRI ArcView GIS 3.2a. The pregnant female captured 9th May 2012 has the size of MCP=67ha and Kernel 95%=0.5ha and the pregnant female captured 12th July 2012 has the size of MCP=82ha and Kernel 95%=0.9ha. Although a fawn could move immediately just after the birth likely others to avoid any risks, they stay at very narrow space significantly, and the size become wider when more time goes by. Furthermore, they mainly have a home range away from human activity area such as forest tracking roads. The habitat environment for the parturition is summarized as 40years old cryptomeria forests with new sprouting shrubs for foods, which are the controlled forest through the thinning and removing shrubs 2 years ago. This means that forest works could cause positive results for the parturition and survival of young. The period of parturition is earlier than highland in Jeju Island, the size of home range is narrower than other countries, and the habitat environment of the shelter for a fawn is similar to previous research in other countries.

The Significance of Sentinel Node Biopsy in Malignant Melanoma and Squamous Cell Carcinoma of Lower Extremities (하지에 발생한 악성흑색종 및 편평상피세포암에서 소속 림프절 생검의 의미)

  • Kim, Jae-Do;Lee, Gun-Woo;Kwon, Young-Ho;Chung, So-Hak
    • The Journal of the Korean bone and joint tumor society
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    • v.16 no.2
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    • pp.69-73
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    • 2010
  • Purpose: Sentinel lymph node (SLNB) is the first confronted lymph node from primary lesion of tumor through lymphatic drainage, which is important for determining early metastasis and setting guidelines for treatment. We reported significant of sentinel lymph node biopsy in malignant melanoma (MM) and squamous cell carcinoma (SCC) of lower extremities. Materials and Methods: Twenty-five cases of surgically treatment and being possible for follow up more than 1 year among the patients who were diagnosed as MM and SCC in this institution from Sep. 2005 to Jan. 2009, and 10 cases of them were performed SLNB. Average age was 64 years old, and 15 cases of male and 10 cases of female were in this group. Results: 3 years overall survival rate was 100% and 3 years disease-free survival rate was 76%. Metastasis occurred in total 6 patients, 4 cases of inguinal lymph nodes, 1 case of soft tissue around knee, 1 case of left achilles tendon. In 15 cases of not performing SLNB, overall survival rate was 93.3% and disease-free survival rate was 73.3%. In 10 cases of performing SLNB, overall survival rate was 100% and disease-free survival rate was 90%. And only 1 case showed positive finding in the biopsy, and none of the 10 cases showed metastasis in follow-up. Conclusion: SLNB leads simpler and less complications compared to prior elective lymph node dissection, and shows high degree of accuracy. Throughout the SLNB, setting guidelines for treatment by accurate staging is thought to be helpful for increasing the survival rate in the patient with MM and SCC.