• 대한치과보철학회지
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• 제55권1호
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• pp.18-25
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• 2017

목적: 이 연구의 목적은 coloring agent의 종류와 적용 횟수가 지르코니아의 색조에 미치는 영향을 알아보는 것이다. 재료 및 방법: 단일구조 지르코니아($15.7mm{\times}15.7mm{\times}2.0mm$)를 준비하여 완성된 시편은 11개 실험군 그룹으로 coloring agent의 종류와 적용 횟수에 따라 a1-a5와 w1-w5로 나누었다. 색조의 측정은 분광측색기를 이용하여 이루어졌다. Coloring agent를 적용시키지 않은 그룹을 대조군으로 설정하였다. 각 그룹의 색차의 정도(${{\Delta}E^*}_{ab}$)와 translucency parameter (TP)를 분석하였다. 측정치는 two-way ANOVA, multiple comparison $Sch{\acute{e}}ffe$ test, Pearson correlation와 linear regression analysis를 이용하여 분석하였다. 결과: Coloring agent의 적용횟수가 증가할수록 두가지 종류 모두에서 지르코니아의 명도는 감소하고 황색계열은 증가했다. Coloring agent는 지르코니아의 투명도에는 영향을 미치지 않았다. 각 그룹 간의 색조차이는 ${0.87{\Delta}E^*}_{ab}$에서 ${9.43{\Delta}E^*}_{ab}$였다. 결론: Coloring agent의 종류와 적용 횟수는 지르코니아의 색조 차이에 영향을 미치지 않았다.

• 한국수소및신에너지학회논문집
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• 제7권2호
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• pp.157-164
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• 1996

The AB5-type metal hydride electrodes using $(LM)Ni_{4.49}Co_{0.1}Mn_{0.205}Al_{0.205}$(LM : Lanthaniumrich Mischmetal) alloy powders(${\leq}200$mesh) which were coated with 25wt% copper in an acidic bath were prepared with or without addition of 10wt% PTFE as a binder. Prior to electrochemical measurements, the electrodes were sintered at $40^{\circ}C$ for 1 and 2hrs in vacuum with Mm(mischmetal) and sponge type Ti getters. The properties such as maximum capacity, cycle life and mechanical strength of the negative electrode have been investigated. The surface analysis of the electrode was also obtained before and after charge-discharge cycling using scanning electron microscope(SEM). From the observations of electrochemical behavior, it was found that the sintered electrode shows a lower maximum discharge capacity compared with non-sintered electrode but it shows a better cycle life. For the both electrodes with or without addition of PTFE binder, the values of mechanical strength were obtained, and their values increased with increasing sintering time. However, there is little difference of discharge capacity for both electrodes.

• Fisheries and Aquatic Sciences
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• 제14권2호
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• pp.73-78
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• 2011

Vibrio parahaemolyticus possesses two flagella systems: polar and lateral flagella for swimming in liquid and swarming on solid surfaces or in viscous environments. To elucidate the pathogenic role of these dual flagella systems, we constructed single- and double-deletion mutants of the lafA and flhAB flagellum genes and investigated their biofilm formation, cell adhesion, and colonization of the small intestine of suckling mice. The double-mutant strain was more impaired in biofilm formation than either of the single-mutant strains. In addition, the lafA, flhAB, and double-mutant strains showed 40%, 45%, and 60%, respectively, lower adherence to HeLa cells than the wild-type strain. Moreover, the lafA, flhAB, and double-mutant strains exhibited 49%, 5.6 and 6.7 times, respectively, lower colonization in a competition assay than the wild-type strain. These findings indicated that polar flagella were more important than lateral flagella for the pathogenesis of V. parahaemolyticus.

• Journal of Microbiology and Biotechnology
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• 제32권2호
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• pp.170-175
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• 2022

3-Hydroxypropionic acid (3HP) is a platform chemical and can be converted into other valuable C3-based chemicals. Because a large amount of glycerol is produced as a by-product in the biodiesel industry, glycerol is an attractive carbon source in the biological production of 3HP. Although eight 3HP-producing aldehyde dehydrogenases (ALDHs) have been reported so far, the low conversion rate from 3-hydroxypropionaldehyde (3HPA) to 3HP using these enzymes is still a bottleneck for the production of 3HP. In this study, we elucidated the substrate binding modes of the eight 3HP-producing ALDHs through bioinformatic and structural analysis of these enzymes and selected protein engineering targets for developing enzymes with enhanced enzymatic activity against 3HPA. Among ten AbKGSADH variants we tested, three variants with replacement at the Arg281 site of AbKGSADH showed enhanced enzymatic activities. In particular, the AbKGSADH^R281Y variant exhibited improved catalytic efficiency by 2.5-fold compared with the wild type.

• Toxicological Research
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• 제27권2호
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• pp.125-131
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• 2011

Through the present study, we produced a monoclonal antibody against aflatoxin B1 (AFB1) using AFB1-carboxymethoxylamine BSA conjugates. One clone showing high binding ability was selected and it was applied to develop a direct competitive ELISA system. The epitope densities of AFB1-CMO against BSA and KLH were about 1 : 6 and 1 : 545, respectively. The monoclonal antibody (mAb) from cloned hybridoma cell was the IgG1 subclass with ${\lambda}$-type light chains. The $IC_{50}s$ of the monoclonal antibody developed for AFB1, AFB2, AFG1 and AFG2 were 4.36, 7.22, 6.61 and 29.41 ng/ml, respectively, based on the AFB1-KLH coated ELISA system and 15.28, 26.62, 32.75 and 56.67 ng/ml, respectively, based on the mAb coated ELISA. Cross-relativities of mAb to AFB1 for AFB2, AFG1 and AFG2 were 60.47, 65.97 and 14.83% in the AFB1-KLH coated ELISA, and 59.41, 46.66 and 26.97% in the mAb coated ELISA, respectively. Quantitative calculations for AFB1 from the AFB1-Ab ELISA and AFB1-Ag ELISA ranged from 0.25 to 25 ng/ml ($R^2$ > 0.99) and from 1 to 100 ng/ml ($R^2$ > 0.99), respectively. The intra- and inter-assay precision CVs were < 10% in both ELISA assay, representing good reproducibility of developed assay. Recoveries ranged from 79.18 to 91.27%, CVs ranged from 3.21 to 7.97% after spiking AFB1 at concentrations ranging from 5 to 50 ng/ml and following by extraction with 70% methanol solution in the Ab-coated ELISA. In conclusion, we produced a group specific mAb against aflatoxins and developed two direct competitive ELISAs for the detection of AFB1 in feeds based on a monoclonal antibody developed.

• Journal of Chest Surgery
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• 제38권1호
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• pp.44-49
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• 2005

흥선종양은 비교적 흔한 종격종 종양이나 이제까지 병리학적 분류가 통일된 것이 없었으며 또한 치료 및 예후와의 연관성이 잘 확립되어 있지 않았다. 최근에서야 WHO 분류가 발표되었고 이에 따른 치료 계획과 치료에 따른 예후와의 상관관계가 보고되기 시작했다. 본 연구는 WHO 분류와 Masaoka병기 그리고 임상양상 간의 상관관계를 조사하였다. 대상 및 방법: 대상환자는 서울아산병원 흉부외과에서 1993년 1월부터 2003년 6월까지 완전절제술을 시행 받았던 흥선종양 환자 98명으로 하였다. WHO 분류의 조사를 위하여 병리조직 slide를 다시 검토하였으며 수술 후 Masaoka병기와의 관련성, 술 후 추가적인 치료와 예후에 대한 관계 및 재발여부에 관하여 의무기록 조사를 통하여 후향적으로 조사하였다. 결과: 98예의 대상 환자 중 남녀 비는 48 : 50이었으며 수술 연령은 평균 $49.6{\pm}13.9$세였다. WHO 분류에 따르면 type A 6명, AB 14명, B1 18명, B2 23명, B3 18명, C 9명이었다. Masaoka 병기와 WHO 분류와의 관계를 보면 Masaoka 병기 I 53명 $(54{\%})$ 중에서 WHO type A 4명, AB 7명, B1 22명, B2 17명, B3 3명이었으며 Masaoka 병기 II 28명$(28.5{\%})$ 중에서는 WHO type A 2명, AB 7명, B1 4명, B2 2명, B3 8명, C 5명이었고 Masaoka병기 III 15명$(15.3{\%})$ 중에서는 WHO type B1 L명, B2 3명, B3 7명, C 4명이었으며 Masaoka병기 IV 2명$(2{\%})$ 중에서는 WHO type B1 1명, B2 1명이었다. 평균 추적 기간은 $28{\pm}6.8$개월이었다. 사망 환자는 3명으로 type B2에서 2명(Masaoka 병기 III, IV), 그리고 type C에서 1명(Masaoka병기 II)이었다 재발 후 생존해 있는 환자는 총 6명이었으며 이 중 type B2에서 2명(Masaoka 병기 III), type B3에서 2명(Masaoka 병기 I, III) type C에서 2명(Masaoka 병기 II)이었다. Kaplan-Meier방법으로 통계 처리한 결과 WHO분류상 type B2에서 5년 생존율은 $90{\%}$ 였으며 type C에서 5년 생존율은 $87.5{\%}$였다. 재발률을 보면 class B2에서 5년 무병 생존율 $80.7{\%}$, B3에서 $81.6{\%}$, C에서 $50{\%}$였다. Log-Rank 방법에서 보면 WHO분류와 생존율, 재발률 사이에 통계학적으로 상관관계가 있는 것으로 나타났다(p<0.05). WHO 분류와 Masaoka분류의 상관 관계를 보면 Spearman correction method출 이용한 통계에서 상관관계 곡선이 slope=0.401 (p=0.023)으로 밀접한 관계가 있다고 하겠다. 결론: WHO분류의 type C의 경우 수술 후 재발률과 사망률이 높으므로 수술 후보다 적극적인 치료와 추적관찰이 필요할 것으로 생각된다. WHO분류와 Masaoka 병기간에는 상호 밀접한 관계가 있는 것으로 생각되며 WHO분류 및 Masaoka병기 모두 흥선종의 예후의 예측 인자가 될 수 있을 것으로 생각된다.

• 미생물학회지
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• 제31권4호
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• pp.292-299
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• 1993

국내에서 분리된 Agrobacterium tumefaciens KU12 는 많은 식물체에서 종양을 유발하여 octopine 을 유일한 탄소원과 질소원으로 이용할 수 있다. A. tumefaciens KU12 내에는 크기가 각각 45.5 kb, 240 kb 및 240 kb 이상인 3종류의 플라스미드가 존재하는 것으로 확인되었다. KU12내에 존재하는 octopine type Ti plasmid 를 확인하기 위하여 플라스미드를 가지고 있지 않은 A. tumefaciens A136 을 direct transformation 방법에 따라 KU12 에서 분리한 플라스미드 시료로 형질전환시킨후 질소원으로 octopine 만을 가지로 있는 AB 최소배지를 이용하여 Ti plasmid 에 의해 형질전환된 형질정환체를 선별하였다. 선별된 형질전환체를 A. tumefaciens KU911 이라고 명명하였으며 KU911 내에는 240 kb 크기의 플라스미드만이 존재하였다. 종양형성능 및 Southern hybridization 을 이용하여 octopine type Ti plasmid 인 pTiKU12 로 명명된 240 kb 크기의 플라스미드가 Ti plasmid 임을 확인되었다.

• 한국수소및신에너지학회논문집
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• 제8권2호
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• pp.79-90
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• 1997

Extensive work has been done on investigating the inner cell pressure characteristics of sealed type Ni-MH battery in which Zr-Ti-Mn-V-Ni alloy is used as anode. The inner cell pressure of this type Ni-MH battery much more increases with the charge/discharge cycling than that of the other type Ni-MH battery where commercialized $AB_5$ type alloy is used as anode. The increase of inner cell pressure in the sealed type Ni/MH battery using Zr-Ti-Mn-V-Ni alloy system is mainly due to the accumulation of oxygen gas during charge/discharge cycling. The accumulation of oxygen gas arises mainly due to the low rate of oxygen recombination on the MH electrode surface during charge/discharge cycling. The difference of oxygen recombination rate between $AB_5$ type electrode and Zr-Ti-Mn-V-Ni electrode is caused by the difference of electrode reaction surface area resulting from different particle size after their activation and the difference of surface catalytic activity for oxygen recombination reaction, respectively. After EIS analysis, it is identified that the surface catalytic activity affects much more dominantly on the oxygen recombination reaction than the reaction surface area does. In order to suppress the inner cell pressure of Ni-MH battery where Zr-Ti-Mn-V-Ni is used as anode, it is suggested that the surface catalytic activity for oxygen recombination should be improved.

• 한국수소및신에너지학회논문집
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• 제10권4호
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• pp.225-232
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• 1999

Ni-MH 2차 전지의 음극재료로 사용되는 수소저장합금중 이론 방전용량이 가장 높은 $Mg_2Ni$를 기계적 합금법으로 제조하여 각종 첨가물의 첨가에 따른 전기화학적 특성을 조사하였다. $Mg_2Ni$는 고에너지 볼밀인 SPEX 8000을 이용하여 두가지 방법으로 제조하였다. 하나는 Mg, Ni 분말에 첨가물인 $AB_5$, $AB_2$계 수소저장합금과 Ni, Co, Cu를 첨가하여 12시간 볼밀링한 경우이고, 다른 하나는 먼저 Mg, Ni 분말을 1시간동안 볼밀링한 후 $300{\sim}400^{\circ}C$에서 열처리하여 $Mg_2Ni$를 제조한 후 여기에 첨가물을 10wt% 첨가하여 12 시간동안 볼밀할 경우이다. 이 볼밀링한 복합분말을 상온에서 $754tons/cm^2$의 압력으로 냉간압착하여 디스크 모양의 전극을 제조하였다. 실험결과 볼밀링 후 열처리를 거친 합금분말의 경우가 그렇지 않은 경우에 비해 전극의 방전용량이 높았으며, Ni을 첨가한 경우는 방전용량을 증가시키고 Co를 첨가한 경우는 싸이클 특성이 향상되었다. 특히 $Mg_2Ni$에 Ni을 10wt%를 첨가하여 12시간 볼밀한 경우 $Mg_2Ni$의 최대 방전용량은 546mAh/g.alloy으로 이론용량의 약 55%에 달했다.

• 음성과학
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• 제15권3호
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• pp.159-173
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• 2008

The purpose of this study was to use fiber-optic nasolaryngoscope to find out differences in laryngeal behavior between persons who stutter(PS) and those who do not stutter(NS) upon their utterance. To meet the goal above, this study took 5 NS and 5 PS respectively as a part of sampling, so that they were all asked to join an experiment hereof. As a result, this study came to the following findings: First, there was not any significant difference in laryngeal behavior of uttering spoken languages between stuttering group and control. Second, there were some differences in laryngeal behavior of repetition and prolongation, which were a sort of disfluency revealed in the utterance of nonfluent spoken languages between stuttering group and control. Third, as reported by prior studies, it was found that there were differences in laryngeal abehavior of stutterer group's nonfluent spoken languages depending upon stuttering types. In this study, a variety of laryngeal behavior unreported in prior studies could be found. In addition, it was notable that stutterers showed different laryngeal behavior depending on their personal stuttering types. On block condition, Subject 1 showed laryngeal behavior of fAB, INT and fAD; Subject 2 showed laryngeal behavior of fAB, fAD and rAD; Subject 3 showed laryngeal behavior of fAD and rAD; Subject 4 showed only laryngeal behavior of fAD; and Subejct 5 showed laryngeal behavior of fAB, fAD and rAD. Summing up, these findings imply that when stutterers utter nonfluent words, they may reveal a variety of laryngeal behavior depending on their personal stuttering types. Moreover, it is found that there are more or less differences in the utterance of nonfluent spoken languages between NS and stuttering ones. In particular, it is interesting that one common trait of nonfluent spoken languages uttered by PS is evidently excessive laryngeal stress, no matter which type of stuttering they reveal.