• 한국동물위생학회지
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• 제36권2호
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• pp.111-119
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• 2013

The aim of this study was to investigate the isolation frequency and antimicrobial resistance of Escherichia coli (E. coli) and Enterococcus spp. from domestic beef and pork on sale in Seoul, Korea. A total of 106 (10.4%) E. coli and 114 (11.2%) Enterococcus spp. from 635 domestic beef and 381 pork samples were isolated and examined for susceptibility to 15 and 11 antimicrobial agents, respectively. The most frequent antimicrobial resistance observed in E. coli isolates was to ampicillin (38.6%), followed by streptocmycin (34.9%) and tetracycline (32.0%). The most frequent antimicrobial resistance in E. faecium isolates was to erythromycin (53.8%) and rifampin (46.1%), and in E. faecalis isolates was to tetracycline (55.7%) and rifampin (55.0%). Among the isolates, multi-drug resistant (MDR) E. coli and Enterococcus spp. strains showing resistances to more than two antimicrobial agents tested were 10.4% and 11.2%, respectively. As a result, appropriate protocols for antimicrobial agents and strategies to reduce antimicrobial resistance will be needed in future.

• 한국광과학회:학술대회논문집
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• 한국광과학회 2002년도 정기총회 및 제9회 광과학 학술심포지움 논문초록
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• pp.63-63
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• 2002

• Archives of Pharmacal Research
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• 제11권3호
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• pp.218-224
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• 1988

The preparation of Clostridium butyricum is used as a normalizing agent for human intestinal flora. When the microbe is simultaneously used with rifampicin, it is inactivated by the antibiotic. To develop rifampicin-resistant mutants, rifampicin-sensitive strain Miyairi II 588 of C. butyricum was treated with nitrosoguanidine (NTG). To ensure stable resistance to rifampicin, we examined whether the resistance was plasmid-mediated or chromosome-mediated. It was found that the resistance of four mutant strains was not mediated by its inherent plasmid, but by the chromosomal mutation. These strains were examined for the susceptibility and resistance to other antituberculosis agents and antibiotics. The results showed that these mutants were resistant to the high concentration of the antituberculosis agents.

• Natural Product Sciences
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• 제6권1호
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• pp.36-39
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• 2000

Acorenone, a diterpene isolated from Acorus gramineus, showed strong resistance inhibitory activity against multi-drug resistant microorganisms such as Staphylococcus aureus SA2, which has resistance to 10 usual antibiotics including chloramphenicol (Cm). At the level of $5\;{\mu}g/ml$ when combined with $50\;{\mu}g/ml$ of Cm. Bacterial resistance to Cm is due to the presence in resistant bacteria of an enzyme, chloramphenicol acetyltransferase (CAT), which catalyses the acetyl-CoA dependent acetylation of the antibiotic at C-3 hydroxyl group. To elucidate the mechanism of resistant inhibitory effect, the acorenone which had the strongest resistant inhibitory activity, was investigated on the CAT assay. As the result, the combination of Cm and acorenone showed the strongest inhibitory activity on CAT as noncompetitive and dose dependent manner.

• 대한수의학회지
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• 제52권4호
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• pp.285-288
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• 2012

Salmonella I 4,[5],12:i:- was a monophasic variant of Salmonella (S.) Typhimurium and notorious for re-emerging candidate which would replace S. Typhimurium DT104 for antibiotic resistance. Recently, isolation rate was increased on human and industrial animals but there was no case in domestic animals but human in Korea. This was first isolation case from domestic animals in Korea. The five isolates from feces of duck (n = 3), chicken (n = 1), and wild bird (n = 1) showed antibiotic resistance against cephems and aminoglycosides. These means that the spread of emerging bacterial pathogens to domestic animals and the need of systemic management for Salmonella I 4,[5],12:i:-.

• 한국미생물·생명공학회지
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• 제32권1호
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• pp.47-51
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• 2004

암세포가 특정 항암제에 의해 내성을 획득하면 구조가 상이한 타 항암제에도 교차내성을 나타내는 이른바 암세포의 다약제 내성이 암 화학요법에 있어서 가장 심각한 문제가 되고 있다. 본 연구에서는 다약제 내성 암세포주인 CL02 세포를 이용하여 cellulose 용해성 점액세균인 Sorangium cellulosum의 60여종의 균주를 대상으로 다약재 내성 암세포에 유효한 항암물질을 탐색하는 과정에서, 균주 JW1006의 대사산물에서 강한 증식억제 활성을 발견하고 그 활성 본체로서 macrolide계 화합물인 Disorazoles $A_1$과 $A_2$를 분리하였다 Disorazoles $A_1$과 $A_2$는 인체기원의 암세포에 대해 모두 강한 세포독성($IC_{50}$ ＜0.04 ng/$m\ell$)을 나타낼 뿐 아니라 다약제내성 세포주인 CL02와 cisplatin내성 세포주인 CP70에 대해서 감수성 세포주와 동일한 활성을 나타내어 다약제 내성을 극복하는 우수한 활성 물질임을 확인하였다

• Earthquakes and Structures
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• 제7권6호
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• pp.1187-1221
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• 2014

The uplifting and rocking of slender, free-standing structures when subjected to ground shaking may limit appreciably the seismic moments and shears that develop at their base. This high-performance seismic behavior is inherent in the design of ancient temples with emblematic peristyles that consist of slender, free-standing columns which support freely heavy epistyles together with the even heavier frieze atop. While the ample seismic performance of rocking isolation has been documented with the through-the-centuries survival of several free-standing ancient temples; and careful post-earthquake observations in Japan during the 1940's suggested that the increasing size of slender free-standing tombstones enhances their seismic stability; it was George Housner who 50 years ago elucidated a size-frequency scale effect that explained the "counter intuitive" seismic stability of tall, slender rocking structures. Housner's 1963 seminal paper marks the beginning of a series of systematic studies on the dynamic response and stability of rocking structures which gradually led to the development of rocking isolation-an attractive practical alternative for the seismic protection of tall, slender structures. This paper builds upon selected contributions published during this last half-century in an effort to bring forward the major advances together with the unique advantages of rocking isolation. The paper concludes that the concept of rocking isolation by intentionally designing a hinging mechanism that its seismic resistance originates primarily from the mobilization of the rotational inertia of its members is a unique seismic protection strategy for large, slender structures not just at the limit-state but also at the operational state.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.421-424
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• 2004

As the deep sub-micron devices are recently integrated high package density, novel process method for sub $0.1{\mu}m$ devices is required to get the superior thin gate oxide characteristics and reliability. However, few have reported on the electrical quality and reliability on the thin gate oxide. In this paper I will recommand a novel shallow trench isolation structure for thin gate oxide $30{\AA}$ of deep sub-micron devices. Different from using normal LOCOS technology, novel shallow trench isolation have a unique 'inverse narrow channel effects' when the channel width of the devices is scaled down shallow trench isolation has less encroachment into the active device area. Based on the research, I could confirm the successful fabrication of shallow trench isolation(STI) structure by the SEM, in addition to thermally stable silicide process was achiever. I also obtained the decrease threshold voltage value of the channel edge and the contact resistance of $13.2[\Omega/cont.]$ at $0.3{\times}0.3{\mu}m^2$. The reliability was measured from dielectric breakdown time, shallow trench isolation structure had tile stable value of $25[%]{\sim}90[%]$ more than 55[sec].

• Earthquakes and Structures
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• 제17권4호
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• pp.425-434
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• 2019

The most effective passive vibration control and seismic resistance options in a reinforced concrete (RC) high-rise building (HRB) are the base isolation and the tuned mass damper (TMD) system. Many options, which may be suitable or not for different soil types, with different types of bearing systems, like rubber isolator, friction pendulum isolator and tension/compression isolator, are investigated to resist the base straining actions under five different earthquakes. TMD resists the seismic response, as a control system, by reducing top displacement or the total movement of the structure. Base isolation and TMDs work under seismic load in a different way, so the combination between base isolation and TMDs will reduce the harmful effect of the earthquakes in an effective and systematic way. In this paper, a comprehensive study of the combination of TMDs with three different base-isolator types for three different soil types and under five different earthquakes is conducted. The seismic response results under five different earthquakes of the studied nine RC HRB models (depicted by the top displacement, base shear force and base bending moment) are compared to show the most suitable hybrid passive vibration control system for three different soil types.

• 한국축산식품학회지
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• 제33권2호
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• pp.239-243
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• 2013

Salmonella Enteritidis is responsible for causing foodborne diseases upon consumption of egg products. While cases of S. Enteritidis isolation from eggs have been reported in other countries, no such cases have previously been reported in Korea. In this study, we report the first isolation and identification of S. Enteritidis from domestically distributed eggs in Korea. Eggs were collected from eight countrywide grocery stores during different seasons between 2011 and 2012. Egg contents and washing solution of egg shells were incubated in buffered peptone water, and the enriched broth was further enriched in tetrathionate broth and Rappaport-Vassiliadis. The secondary enriched broth was streaked on xylose lysine desoxycholate agar. The suspected colonies were confirmed to S. Enteritidis by a biochemical test, serotyping, and PCR test. Genetic relatedness among the isolates was analyzed using Diversilab Salmonella kit. Three strains of S. Enteritidis were isolated from egg contents and egg shells collected from grocery stores of the Eumseong-city in the fall of 2011. All three stains showed resistance to chloramphenicol, streptomycin, nalidixic acid, and ampicillin by the disk diffusion method. In addition, the isolates showed more than 99% DNA homology, indicating that they were presumably identical strains. Therefore, there is a requirement to monitor and control against S. Enteritidis from eggs in Korea.