• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1837-1840
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• 2006

Because there are no unified nomenclature systems for either GES-type or IBC-type extended-spectrum ${\beta}-lactamases$ (ESBLs), we propose a unified and definitive nomenclature system for GES/IBC-type ESBLs. This proposed nomenclature update is greatly helpful in two points: (i) it would not confuse microbiologists studying GES-type ESBLs, fundamentally preventing misleading nomenclature of these antibiotic resistance genes, and (ii) the definitive renaming of GES/IBC-type ESBLs can help some researchers to correctly designate new GES-type ESBLs such as novel enzymes identified trom some nationwide surveys.

• 대한치과보철학회지
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• 제43권5호
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• pp.599-610
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• 2005

Purpose: The success of the bonding between electroformed gold and ceramic is dependent on the surface treatment of the pure gold coping. The purpose of this study was to evaluate the bonding strength between the electroformed gold and ceramic with varying surface treatment. Materials and methods: A total of 32 disks,8 were using conventional ceramometal alloy, 24 were using electroforming technique as recommended by manufacturer, were prepared. 24 electroformed disks were divided 3 groups according to surface treatment, i.e. 50 microns aluminium oxide sandblasting(GES-Sand), gold bonder treatment(GES-Bond) and $Rocatec^{TM}$ system(GES-Rocatec). For control group of conventional alloy 50 microns aluminium oxide treatment was done(V-Supragold). Energy dispersive x-ray analysis and scanning electron microscope image were observed. Using universal testing machine, shear bond strength and bonding failure mode at metal-porcelain interface were measured. Results and Conclusion: The following conclusions were drawn: 1. In the energy dispersive x-ray analysis, the Au was main component in electroformed gold(99.9wt%). After surface treatment, a little amount of $Al_2O_3(2.4wt%)$ were found in GES-Sand, and $SiO_2(4wt%)$ in GES-Bond. In GES-Rocatec, however, a large amount of $SiO_2(17.4wt%)$ were found. 2. In the scanning electron microscopy, similar pattern of surface irregu larities were observed in V-Supragold and GES-Sand. In GES-Bond, surface irregularities were increased and globular ceramic particles were observed. In GES-Rocatec, a large amount of silica particles attached to metal surface with increased surface irregularities were observed. 3. The mean shear bond strength values(MPa) in order were $22.9{\pm}3.7(V-Supragold),\;22.1{\pm}3.8(GES-Bond),\;20.1{\pm}2.8(GES-Rocatec)\;and\;13.0{\pm}1.4(GES-Sand)$. There was no significant difference between V-Supragold, GES-Bond, and GES-Rocatec. (P>0.05) 4. Most bonding failures modes were adhesive type in GES-Sand. However, in V-Supragold, GES-Bond and GES-Rocatec, cohesive and combination failures were commonly observed. From the result, with proper surface treatment method electroformed gold may have enough strength compare to conventional ceramometal alloy.

• 한국분말야금학회:학술대회논문집
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• 한국분말야금학회 2006년도 Extended Abstracts of 2006 POWDER METALLURGY World Congress Part2
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• pp.844-845
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• 2006

For microelectronic circuits, the main type of failure is thermal fatigue. Therefore, the search for matched coefficients of thermal expansion (CTE) of packaging materials in combination with a high thermal conductivity is the main task for developments of heat sink materials electronics, and good mechanical properties are also required. The aim of this work is to develop copper matrix composites reinforced with carbon nanofibers to meet these requirements. In this paper, a technology for obtaining a homogeneous mixture of copper and nanofibers will be presented and the microstructure and properties of consolidated samples will be discussed.

• Journal of Korean Biological Nursing Science
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• 제25권1호
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• pp.73-85
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• 2023

Purpose: This study focused on identifying the interaction effects of genetic and lifestyle-environmental factors on the development of type 2 diabetes mellitus (T2D). Methods: Study subjects were selected from the Korean Genome and Epidemiology Study (KoGES) from 2001 to 2014. Data on genetic variations, anthropometric measurements, biochemical data, and seven lifestyle factors (diet, physical activity, alcohol drinking, smoking, sleep, depression, and stress) were obtained from 4,836 Koreans aged between 40 and 59 years, including those with T2D at baseline (n = 1,209), newly developed T2D (n= 1,298) and verified controls (n = 3,538). The genetic risk score (GRS) was calculated by using 11 single-nucleotide polymorphisms (SNPs) related to T2D development and the second quartile was used as the reference category. A Cox proportional hazards regression model was used to evaluate the associations of GRS and lifestyle factors with T2D risk, controlling for covariates. Results: Multivariate regression analysis revealed that GRS was the strongest risk factor for T2D, and body mass index (BMI), smoking, drinking, and spicy food preference also increased the risk. Lifestyle/environmental factors that showed significant interactions with GRS were BMI, current smoking, current drinking, fatty food preference, and spicy food preference. Conclusions: Interactions between genetic factors and lifestyle/environmental factors were associated with an increased risk of T2D. The results will be useful to provide a new perspective on genetic profiling for the earlier detection of T2D risk and clues for personalized interventions, which might be more effective prevention strategies or therapies in individuals with a genetic predisposition to T2D.

• 대한간호학회지
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• 제52권1호
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• pp.24-35
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• 2022

Purpose: This study investigated the incidence and risk factors of cataract in people with diabetes mellitus (DM) using data from Ansan cohort of the Korean Genome and Epidemiology Study (KoGES). Methods: Data from a total of 329 patients with type 2 DM without cataract who participated in Ansan cohort of the KoGES from baseline survey (2001-2002) to fifth follow-up visit (2011-2012) were examined. The characteristics of the subjects were analyzed with frequency and percentage, and mean and standard deviation. Cataract incidence was measured as incidence proportion (%). For risk factors of cataract, hazard ratio (HR) and 95% confidence interval (CI) were obtained using the Cox proportional hazard model. Results: The cataract incidence over a 10-year follow-up period was 19.1% (15.1 in males and 25.8 in females), and mean age at the incidence of cataract was 63.48 years (61.58 years in males and 65.31 years in females). Age (HR=1.09, 95% CI=1.05-1.13) and HbA1c (HR=1.21, 95% CI=1.07-1.37) or the duration of DM (HR=1.05, 95% CI=1.00-1.09) were found to be independently associated with cataract development. Conclusion: Cataract development in people with DM is common, and its likelihood increases with age, HbA1c, and the duration of DM. Considering negative effect of cataract on their quality of life and economic burden, nurses should identify people with DM at a higher risk of cataract development, and plan individual eye examination programs to detect cataract development as early as possible.

• 한국분말재료학회지
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• 제13권5호
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• pp.321-326
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• 2006

Electronic packaging involves interconnecting, powering, protecting, and cooling of semiconductor circuits fur the use in a variety of microelectronic applications. For microelectronic circuits, the main type of failure is thermal fatigue, owing to the different thermal expansion coefficients of semiconductor chips and packaging materials. Therefore, the search for matched coefficients of thermal expansion (CTE) of packaging materials in combination with a high thermal conductivity is the main task for developments of heat sink materials electronics, and good mechanical properties are also required. The aim of this work is to develop copper matrix composites reinforced with carbon nanofibers. The advantages of carbon nanofibers, especially the good thermal conductivity, are utlized to obtain a composite material having a thermal conductivity higher than 400 W/mK. The main challenge is to obtain a homogeneous dispersion of carbon nanofibers in copper. In this paper, a technology for obtaining a homogeneous mixture of copper and nanofibers will be presented and the microstructure and properties of consolidated samples will be discussed. In order to improve the bonding strength between copper and nanofibers, different alloying elements were added. The microstructure and the properties will be presented and the influence of interface modification will be discussed.

• Journal of Neurogastroenterology and Motility
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• 제25권3호
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• pp.387-393
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• 2019

Background/Aims Delayed gastric emptying (GE) is associated with high morbidity and mortality in subjects with diabetes. The aim of this study is to investigate associations between GE time and the major cardiovascular events (coronary heart diseases and ischemic stroke) in diabetic subjects with upper gastrointestinal (UGI) symptoms. Methods Among 259 subjects with chronic UGI symptoms who underwent gastric emptying study (GES) over 13 years, 122 diabetic subjects without gastric surgery and/or rapid GE were enrolled in this study. We also gathered data about baseline demographics, clinical characteristics, estimated GE half-time (GE T½) and incidence of cardiovascular events following GES. Results The mean age of subjects was 64.0 ± 17.4 years. There were 86 women and 104 subjects with type 2 diabetes. There were 52 (42.6%) subjects with normal GE, 50 (41.0.%) subjects with mild delayed GE, and 20 (16.4%) subjects with marked delayed GE. During follow-up (median, 207 weeks), cardiovascular events occurred in 7 (13.5%) subjects with normal GE, 4 (8.0%) subjects with mild delayed GE and 7 (35.0%) subjects with marked GE (P = 0.015). Univariate analysis showed that GE T½ was significantly associated with incidence of cardiovascular events (crude OR, 1.74; 95% CI, 1.12-2.69; P = 0.014). In a multivariate model, association between GE T½ and incidence of cardiovascular events remained statistically significant after adjustment for baseline characteristics and comorbidities (adjusted OR, 1.94; 95% CI, 1.21-3.12; P = 0.006). Conclusion A delay of GE was associated with an increased incidence of cardiovascular events in diabetic subjects with chronic UGI symptoms.

• 한국산학기술학회논문지
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• 제15권4호
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• pp.2295-2302
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• 2014

장내세균 가운데서 가장 빈번하게 나오는 대장균에서 Extended-Spectrum ${\beta}$-Lactamase(ESBL)를 생성하는 효소의 검출빈도와 이들 균주의 ESBL 효소의 유형을 구분하는 것이 이 연구의 목적이다. 균주는 충청지역 (대전, 충남, 충북)병원에서 2013년 2월부터 7월까지 6개월간 282 대장균 균주 중 ESBL을 생성하는 74균주(26.2%)를 수집하였다. 충청지역에 ESBL 균주를 포함한 대장균의 항균제 내성률은 Aztreonam 30.8%, Cefotaxim 30.9%, 그리고 Ceftazidime 32.2%로 나타났으며 ESBL을 생성하는 균주는 ${\beta}$-lactam 항균제인 Aztreonam에 58.1%, Cefotaxim 100%, 그리고 Ceftazidime 63.5%의 내성률을 보였다. 동정된 ESBL 균의 CTX-M-2은 48 균주, CTX-M-8은 20 균주, PER-1 28 균주, 그리고 VEB-1 26 균주에서 나왔다. GES-1 형은 74균주 중 2균주가 충남에서만 유일하게 나타났다. ESBL 검출빈도와 유형의 정확한 파악은 병원감염관리와 항균제 처방에 도움이 될 것이다.

• 전자공학회논문지
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• 제52권3호
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• pp.173-180
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• 2015

외곽 침입 탐지를 위한 전자보안 펜스 시스템은 광망, 장력, 자력 등 다양한 시스템이 개발되어 국가 보안시설에 설치되고 있으나, 실외에 설치가 되는 시스템으로 환경 잡음에 따른 오경보의 발생에 따라 현장적용에 불편함이 크다. 본 논문에서 연구하는 마찰대전 방식의 전자보안펜스 시스템은 침입에 따른 감지 성능뿐 아니라, 경제성, 시공편리성, 유지보수 측면에서 많은 장점을 가지고 있으나, 환경 잡음에 따른 신뢰성 개선이 필요하다. 본 연구의 목적은 환경 잡음에 따른 오경보 감소에 대한 연구를 하는 것이다. 기존의 마찰대전 방식 전자보안펜스 시스템은 펜스 침입 신호의 크기를 분석하여 침입 경보를 결정했으나 강풍과 같은 환경잡음에 의해서도, 동일한 신호의 크기가 발생되어 오경보의 해석에 어려움이 있었다. 오경보 감소방안 연구를 위해 서울시립대학교 교내의 온실 실험실 Fence 위에 시스템을 설치하였고, 환경잡음 신호와의 관계를 분석하기 위해 온도, 풍속, 습도 등에 대한 데이터를 별도로 수집하였다. 수집된 신호는 고속푸리에 변환 FFT(Fast Fourier Transform)를 이용해 주파수 특성을 분석하여, 침입신호와 환경잡음신호를 구분하는 알고리즘으로 개선하였다. 제안된 신호침입 알고리즘의 적용 전 후 데이터를 수집, 분석한 결과, 알고리즘 적용 후, 약 98%의 개선이 있음을 확인하였다. 실제 주요보안 시설에 설치할 경우 주변 잡음신호에 대해 신뢰성을 향상할 수 있는 알고리즘인 것을 확인하였다.

• Nutrition Research and Practice
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• 제18권2호
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• pp.257-268
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• 2024

BACKGROUND/OBJECTIVES: This study investigated the relationship between adherence to the Mediterranean diet among Korean baby boomers and their levels of psychosocial stress. SUBJECTS/METHODS: The study included 1,656 adults (889 men and 797 women) born between 1955 and 1963 who participated in the 2005-2006 survey of the community-based Korean Genome and Epidemiology Study (KoGES). The Mediterranean-type diet score (MTDS) was calculated from the semi-quantitative food frequency questionnaire (SQFFQ) data. The psychosocial stress levels were calculated using the psychosocial well-being indexshort form (PWI-SF). Logistic regression analyses were performed to analyze the association between the MTDS (tertiles) and the prevalence of high psychosocial stress by gender. RESULTS: The ranges of the MTDS tertile groups were T1 (20-33 points), T2 (34-37 points), and T3 (38-39 points) for men, T1 (20-33 points), T2 (34-37 points), and T3 (38-48 points) for women. In both men and women, the consumption of whole grains, potatoes, fruits, vegetables, legumes, and fish increased with higher MTDS, while the consumption of red meat and dairy products decreased (P for trend < 0.05). As MTDS score increased the intake of energy, fiber, vitamins, and minerals (P for trend < 0.05). Men in the highest MTDS tertile had a 41% lower odds ratio (OR) of high psychosocial stress compared with those in the lowest tertile (OR, 0.59; 95% confidence interval [CI], 0.38-0.91). Similarly, women in the highest tertile of the MTDS had a 39% lower OR of high psychosocial stress compared with those in the lowest tertile (OR, 0.61; 95% CI, 0.40-0.95). CONCLUSION: Promoting adherence to the Mediterranean diet among baby boomers may have a positive impact on reducing their levels of psychosocial stress.