• 한국전기전자재료학회논문지
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• 제13권9호
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• pp.729-734
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• 2000

Recently, Very Large Scale Integrated (VLSI) circuit & deep-submicron bulk Complementary Metal Oxide Semiconductor(CMOS) devices require gate electrode materials such as metal-silicide, Titanium-silicide for gate oxides. Many previous authors have researched the improvement sub-micron gate oxide quality. However, few have reported on the electrical quality and reliability on the ultra thin gate oxide. In this paper, at first, I recommand a novel shallow trench isolation structure to suppress the corner metal-oxide semiconductor field-effect transistor(MOSFET) inherent to shallow trench isolation for sub 0.1${\mu}{\textrm}{m}$ gate oxide. Different from using normal LOCOS technology deep-submicron CMOS devices using novel Shallow Trench Isolation(STI) technology have a unique"inverse narrow-channel effects"-when the channel width of the devices is scaled down, their threshold voltage is shrunk instead of increased as for the contribution of the channel edge current to the total channel current as the channel width is reduced. Secondly, Titanium silicide process clarified that fluorine contamination caused by the gate sidewall etching inhibits the silicidation reaction and accelerates agglomeration. To overcome these problems, a novel Two-step Deposited silicide(TDS) process has been developed. The key point of this process is the deposition and subsequent removal of titanium before silicidation. Based on the research, It is found that novel STI structure by the SEM, in addition to thermally stable silicide process was achieved. We also obtained the decrease threshold voltage value of the channel edge. resulting in the better improvement of the narrow channel effect. low sheet resistance and stress, and high threshold voltage. Besides, sheet resistance and stress value, rms(root mean square) by AFM were observed. On the electrical characteristics, low leakage current and trap density at the Si/SiO$_2$were confirmed by the high threshold voltage sub 0.1${\mu}{\textrm}{m}$ gate oxide.

• 농약과학회지
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• 제18권3호
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• pp.161-167
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• 2014

Strobilurin계 살균제인 azoxystrobin에 대한 잿빛곰팡이병균 Botrytis cinerea의 저항성 발현 여부를 조사하였다. B. cinerea 균주는 $1.0{\mu}g\;mL^{-1}$의 azoxystrobin에 대한 반응을 기준으로 실험 균주 중에서 46.5%가 감수성 균주로, 53.5%가 저항성 균주로 판명되었다. 병원균을 분리한 지역별로 저항성 균주의 출현 비율은 경기, 경남, 부산에서 28.6, 41.9, 36.8%이었으며, 충남에서 81.1%로 다른 지역보다 높게 나타났다. 기주별로 저항성 균주는 딸기, 오이, 토마토에서 분리한 균주에서는 각각 68.0, 40.0, 50.0%, 고추에서는 9.1%만이 나타났다. Azoxystrobin에 대해서 감수성이었던 B. cinerea 11-20은 kresoxim-methyl과 trifloxystrobin에 대해서도 감수성 반응을 보였으며, 저항성 균주인 11-74는 3종의 살균제 모두에 대해서 교차 저항성이 있음을 보여 주었다. 본 실험의 결과 실험에 사용한 B. cinerea 균주의 53.5%가 저항성 반응을 보일 정도로 높은 저항성 출현율을 보였으며, 동일 계열의 살균제에 대한 교차 저항성 반응을 보이고 있기 때문에, 포장에서 strobilurin계 살균제에 대한 철저한 관리가 요구되어진다.

• 한국수산과학회지
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• 제54권4호
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• pp.388-396
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• 2021

Antimicrobial resistance patterns of Escherichia coli were investigated. Strains were isolated from 310 shellfish, 36 crustaceans, and 12 fish collected off the West Coast of Korea from April 2019 to October 2020. Two hundred and ninety-five E. coli strains were isolated from shellfish, 100 from crustaceans, and 54 from fish. Strains isolated from shellfish showed the highest resistance to ampicillin (27.5%), whereas those from crustaceans were resistant to sulfisoxazole (30.0%) and those from fish were resistant to ampicillin (59.3%) and sulfisoxazole (59.3%). Ceftazidime resistance was observed in strains isolated from short neck and hard clams, whereas gentamicin resistance was observed in strains from fish. Multi-drug resistance was observed in 56 strains (48.7%) isolated from shellfish, 11 (28.2%) from crustaceans and 27 (73.0%) from fish. Depending on the source of isolation, the strains showed specific antimicrobial resistance tendency. Strains isolated from shellfish showed 12 different multi-drug resistance patterns, whereas those from crustaceans showed high resistance (59%) to a single antimicrobial agent and those from fish showed a broad trend of multi-drug resistance to more than eight antimicrobials.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.717-722
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• 2003

To improve the shock resistance of the microdrive under non-operating conditions, an isolator was attached to the contacting part of the microdrive. Through FE analysis, design parameters for satisfying the allowable acceleration level of the spindle motor bearing part were presented, which is a most possible critical part of the microdrive.

• 한국식품영양학회지
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• 제10권1호
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• pp.122-126
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• 1997

Bifidobacteria have been known as beneficial inhabitant of human intestine. Therefore, bifidobacteria began to be noticed as a starter in the manufacture of fermented dairy products. Perhaps the key for effective use of bifidobacteria in commercial dairy products is the maintenance of viability of bifidobacteria during large scale preparation of starter culture and distribution of products. So we tried to obtain the bifidobacteria having suitable characteristics for using as a starter in the manufacture of fermented dairy products. Among bifidobacteria isolated from Korean, E-4 strain showed the highest resistance to oxygen. To know whether the selected strain will be fit for manufacture of fermented dairy products, we also investigated resistance of the selected strain to HCI. The selected strain, E-4, was more resistant to environmental stresses such as oxygen, H2O2 and HCI than Bifidobacterium longum known as resistant strain to environmental stresses. According to carbohydrate fermentation patterns and morphological characteristics, E-4 strain was identified as B. bifidum. In conclusion, the selected strain, E-4, was thought to be fit for manufacture of fermented dairy products.

• 약학회지
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• 제33권2호
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• pp.73-79
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• 1989

One hundred and sixteen strains of E. coli isolated from drainage in Seoul city in 1987 and 104 strains of E. coli isolated from stools of domestic animals in suburb of Seoul in 1987 were examined for susceptibilities to 10 antimicrobial agents by the agar dilution method. The susceptibilities of the two groups to each antimicrobial agent were compared and correlations in the antimicrobial susceptibility of the 220 strains of E. coli among the 10 antimicrobial agents were also analyzed. The frequency of resistance strains was highest to tetracycline with 77%, and followed by chloramphenicol, streptomycin, ampicillin, kanamycin and cephalosporin in the descreasing order, tanging from 62% to 10%. Strains resistant to tobramycin, nalidixic acid, gentamicin and amikacin occupied 3 strains, 2 strains, 2 strains and 1 strain respectively.

• Infection and chemotherapy
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• 제50권4호
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• pp.340-345
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• 2018

Frequent isolation of Enterococcus faecalis from root canal treated teeth with apical periodontitis, has proposed the role of this organism in endodontic treatment failures. Different factors have been suggested in the pathogenicity of this organism. In this study, 22 E. faecalis isolates from canals of root-filled teeth were identified, and phenotypic and genotypic characteristics were investigated. No resistance to vancomycin and gentamicin was noted, and most isolates (91%) were susceptible to ampicillin. Biofilm formation was detected in 73% of the isolates and may be considered as the most important virulence factor involved in the pathogenesis of these isolates.

• 농약과학회지
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• 제19권3호
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• pp.329-334
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• 2015

병든 토마토, 딸기, 오이 등의 열매에서 분리한 86개의 Botrytis cinerea의 균주를 가지고 한천희석법을 통하여 mepanipyrim의 균사생장 억제효과를 조사하였으며, $EC_{50}$값을 계산하여 저항성 모니터링을 실시하였다. 병원균의 저항성 모니터링을 PDA 배지에서 실시할 경우 mepanipyrim의 균사생장 억제효과를 정확하게 검정할 수 없었으나, FGA 배지를 사용하였을 때에는 감수성과 저항성 반응을 뚜렷하게 구분할 수 있었다. 실험에 사용한 B. cinerea의 86개 균주를 $1.0{\mu}g\;mL^{-1}$의 $EC_{50}$값을 가지고 감수성과 저항성을 구분하였으며, 전체 균주 중에서 20개인 23.3%가 저항성균으로 분류되었다. 지역에 따라서 저항성균의 분리비에는 차이가 있었는데, 경기, 경남/부산, 그리고 충남에서 각각 분리한 균주 중에서 저항성균의 비율은 28.6, 33.3, 12.8%로, 경남/부산 지역에서 가장 높았다. Mepanipyrim에 대한 저항성균은 pyrimethanil에 대해서도 교차저항성을 보였으며, 오이 자엽에 대한 병원성을 감수성 균주와 비교해 보아도 전혀 떨어지지 않았다. 따라서 포장에서 anilinopyrimidine계 살균제를 효과적으로 사용하기 위해서 적극적인 관리가 필요한 상태이다.

• 식물병연구
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• 제21권1호
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• pp.20-23
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• 2015

A sequential planting method was developed to screen rice plants with durable resistance against rice blast in a short time, and applied for several years in Korean rice breeding program. In this study, we showed the advantages of a sequential planting method compared to other pathogenicity tests. The correlation analysis among three pathogenicity tests and other factors demonstrated that durable resistance depended on the average of diseased leaf area and the number of compatible pathogens. Significant correlations were found in the nursery test but not in the field test result. In addition, we traced changes in the pathogen population during sequential planting stages through re-isolation of the pathogen. The portion of compatible pathogens was increased during sequential planting. Through this study, we provide an effective sequential planting method and direction of durable resistance in a breeding program.

• Journal of Microbiology and Biotechnology
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• 제8권4호
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• pp.388-398
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• 1998

A bacterium which is resistant to both mercury and cadmium, and also capable of utilizing phenol as a carbon and energy source, was isolated from the Kumho River sediments near Kangchang Bridge, Taegu, Korea. The isolate was labeled Pseudomonas sp. KM10 and characterized. The bacteria grew in 4 mM $CdCl_2$and in $70{\mu}M$ $HgCl_2$. The bacteria efficiently removed over 90% of 1 g/l phenol within 30 h. In the presence of 1.250 g/l phenol, the growth of the microorganism was slightly retarded and the microorganism could not tolerate 1.5 g/l phenol. Curing of plasmid from the bacteria was carried out to generate a plasmidless strain. Subsequent experiments localized the genes for phenol degradation in plasmid and the genes for mercury resistance and cadmium resistance on the chromosome. Dot hybridization and Southern hybridization under low stringent conditions were performed to identify the DNA homology. These results showed significant homologies between the some sequence of the chromosome of Pseudomonas sp. KM10 and merR of Shigella flexneri R 100, and between the some sequence of the chromosome of Pseudomonas sp. KM10 and cadA of Staphylococcus aureus pI258. The mechanism of cadmium resistance was efflux, similar to that of S. aureus pI258 cadA, and the mechanism of mercury resistance was volatilization, similar to that of S. flexneri R100 mer.