Bacillus sp . 에 의한 inulin fructotransferase 의 생산

오석진,김수일 한국농화학회 1992 Applied Biological Chemistry (Appl Biol Chem) Vol.35 No.5

Inulin을 di-D-fructofuranose dianhydride(DFA)로 변환시키는 효소인 inulin fructotransferase (depolymerizing)를 생산하는 Bacillus sp.를 토양으로부터 선발, 분리하였으며, 생산된 DFA는 TLC와 HPLC에 의하여 di-D-fructofuranose-1,2' : 2,3'-dianhydride(DFAIII)로 동정되었다. Bacillus sp.는 탄소원으로 J.A. extract, 유기질소원으로 pepton, 무기질소원으로 NH₄H₂PO₄를 사용할 때 가장 높은 효소생산을 나타내었고, 이 균주의 배양 시간에 따른 효소 생산과, 배양액내의 DFAIII 함량을 조사한 결과, 효소생산은 72시간에서 3.1 U/ml, DFAIII는 18시간에서 5.6(g/l)로 각각 최고에 달하였다. 그러나 DFAIII는 배양 18시간부터는 그 함량이 계속 감소하여 72시간에는 검출되지 않았다. 이러한 사실로부터 본 균주가 DFAIII를 분해, 이용하는 효소를 보유한다고 추정할 수 있으며, 이는 intracellular enzyme에 DFAIII를 F₂와 F로 가수분해하는 효소가 존재함을 확인함으로써 검증할 수 있었다.

한국 연안역에서 분리한 식물플랑크톤의 alkaline phosphatase 활성과 용존태 유기인의 이용

오석진,권형규,양한섭,Oh, Seok-Jin,Kwon, Hyeong-Kyu,Yang, Han-Soeb 한국해양학회 2010 바다 Vol.15 No.1

Skeletonema costatum, Chaetoceros didymus, Alexandrium tamarense 그리고 Heterosigma akashiwo의 인 제한에 따른 용존태 유기인(dissolved organic phosphorus; DOP)의 이용성과 alkaline phosphatase(APase)의 활성을 살펴보기 위해 실내실험을 실시하였다. S. costatum, C. didymus, A. tamarense 그리고 H. akashiwo는 인 공급원으로써 용존태 무기인 (dissolved inorganic phosphorus; DIP) 이외에 phosphomonoester와 nucleotide 화합물을 이용하여 성장을 유지할 수 있었다. S. costatum, C. didymus, A. tamarense 그리고 H. a/wshiwo의 APase 활성은 배양액내의 DIP가 각각 $0.30\;{\mu}M$, $0.33\;{\mu}M$, $2.04\;{\mu}M$과 $0.63\;{\mu}M$에서 최초로 활성을 보였으며, 최대활성은 각각 $0.01\;pmol\;cell^{-1}\;hr^{-1}$, $0.11\;pmol\;cell^{-1}\;hr^{-1}$, $1.63\;pmol\;cell^{-1}\;hr^{-1}$와 $0.19\;pmol\;cell^{-1}\;hr^{-1}$였다. APase 활성은 종에 따라 다르게 나타났지만, 최대 활성은 DIP의 흡수속도보다도 높아 인이 제한된 환경에서 효과적으로 DOP를 가수분해하여 성장을 유지 할 수 있을 것으로 보인다. 따라서 DOP의 이용능력은 적조 플링크튼의 성장뿐만 아니라 종간경쟁에도 기여할 것으로 생각된다. Utilization of dissolved organic phosphorus (DOP) and alkaline phosphatase (APase) activity by Skeletonema costatum, Chaetoceros didymus, Alexandrium tamarense and Heterosigma akashiwo under the phosphorus deficient condition were examined in the laboratory. S. costatum, C. didymus, A. tamarense and H. akashiwo could make use of phosphomonoester and nucleotide compounds for the growth of them as a phosphorus source. APase activity of S. costatum, C. didymus, A. tamarense and H. akashiwo began to be activated at dissolved inorganic phosphorus (DIP) concentrations less than $0.30\;{\mu}M$, $0.33\;{\mu}M$, $2.04\;{\mu}M$ and $0.63\;{\mu}M$ respectively, and their maximum APase activity were $0.01\;pmol\;cell^{-1}\;hr^{-1}$, $0.11\;pmol\;cell^{-1}\;hr^{-1}$, $1.63\;pmol\;cell^{-1}\;hr^{-1}$ and $0.19\;pmol\;cell^{-1}\;hr^{-1}$, respectively. Although each phytoplankton species displayed different APase activity for DOP utilization, their maximum APase activities were higher than maximum phosphorus uptake rates, inferring that these species might be able to keep growing under DIP-limited conditions thought utilizing effectively the hydrolized product of DOP. This result also implies that utilization of DOP might contribute to not only the growth of red tide forming phytoplankton but also the interspecific competition among phytoplankton species in coastal environments.

NaOH처리와 SBF침적에 따른 CP-Ti, Ti-6Al-4V 및 ECAP-Ti의 표면 아파타이트 성장

오석진,류재경,이승우,김윤종,한만소,김창규,Oh Seok-Jin,Ruy Jae-Gyeoung,Lee Seung-Woo,Kim Yun-Jong,Han Man-So,Kim Chang-Hyu 한국재료학회 2004 한국재료학회지 Vol.14 No.12

Even though Ti-6Al-4V has gained popularity as an implant material, the possible dissolution of Al and V ions in body fluids remains a matter of concern. Though commercially pure Ti (Cp-Ti) overcomes this problem, the mechanical strength of pure titanium remains very low. Thus, in this experiment Cp-Ti was processed by Equal channel angular processing (ECAP), in order to increase the mechanical strength. The biocompatibility of ECAP-Ti, Cp-Ti and Ti-6Al-4V was examined by the apatite formation on each sample surface, after treating the surface with 5M NaOH and soaking in Simulated body fluids (SBF). Initially, the samples were mechanically polished on silicone carbide paper (#2000). The polished samples were treated with 5M NaOH solution at $60^{\circ}C$ for 24 hours. The NaOH treated samples were washed gently with distill water and dried at $40^{\circ}C$ for 1 day. The dried samples were heat treated in air at $600^{\circ}C$ for 1 hour. The surface morphology of these samples were studied using SEM and XRD. The SEM studies showed network of pores in all samples. The XRD showed oxide layer formation on Cp-Ti and Ti-6Al-4V. samples. However the oxide layer in ECAP-Ti was not substantial. These samples were immersed in SBF, kept at $36.5^{\circ}C$ for seven days period. At the end of 7 days, the apatite formation was confirmed only on Cp-Ti and was not observed in Ti-6Al-4V and ECAP-Ti. These observations of apatite formation relate to the fact that Cp-Ti showed greater oxide layer than other samples. The apatite examined was confirmed as tricalcium phosphate (TCP) using EDS and XRD.

미세조류 4종(Chlorella vulgaris, Nitzschia sp., Phaeodactylum tricornutum, Skeletonema sp.)의 성장에 미치는 발광다이오드 단일파장의 영향

오석진,권형규,전진영,양한섭,Oh, Seok-Jin,Kwon, Hyeong-Kyu,Jeon, Jin-Young,Yang, Han-Seob 해양환경안전학회 2015 해양환경안전학회지 Vol.21 No.1

본 연구는 규조류 Nitzschia sp., Phaeodactylum tricornutum, Skeletonema sp.와 녹조류 Chlorella vulgaris의 성장에 미치는 발광다이오드(LED) 단일파장의 영향을 파악하였다. 4종의 미세조류는 청색 LED(450 nm), 황색 LED(590 nm), 적색 LED(650 nm) 그리고 형광램프(복수파장)에서 배양하였다. Nitzschia sp., P. tricornutum 그리고 Skeletonema sp.의 최대성장속도와 최대세포밀도는 청색 LED에서 가장 높았고 형광램프, 적색 LED, 황색 LED 순이지만, C. vulgaris는 적색 LED에서 가장 높았다. 이는 청색 LED는 다른 파장에 비해서 규조류의 성장을 촉진시키는 작용을 하는 것으로 보인다. 따라서 미세조류의 단일파장 하에서 성장속도는 종 특이성 또는 분류군 특이성을 보이는 것으로 생각된다. 또한 이러한 결과는 향후 LED와 미세조류를 활용한 중금속 오염 퇴적물의 복원을 위한 중요한 정보로 활용 할 수 있을 것이다. We investigated the effect of monochromatic light emitting diode (LED) on the growth of diatoms Nitzschia sp., Phaeodactylum tricornutum, Skeletonema sp. and green algae Chlorella vulgaris. The four microalgae species were cultured under blue LED (450 nm), yellow LED (590 nm), red LED (650 nm) and fluorescent lamp (mixed wavelengths). The maximum growth rates and cell densities of Nitzschia sp., P. tricornutum and Skeletonema sp. were highest under blue LED, followed by fluorescent lamp, red LED and then yellow LED, however those of C. vulgaris were highest under red LED. This result indicates that blue LED is favorable for the growth of diatoms. Thus, the growth of microalgae under monochromatic light might be species-specific or taxon-specific. Also, these results could be used as an important information in future for remediation of heavy metal contamination in the sediments using LED and microalgae.

고성능 금속연료 용해주조 U-Zr 합금계 특성 (초)

오석진,김기환,이종탁,장세정,우윤명,고영모,이찬복 대한금속재료학회 ( 구 대한금속학회 ) 2007 대한금속재료학회 학술대회 개요집 Vol.2007 No.1

Uptake and Excretion of Dissolved Organic Phosphorus by Two Toxic Dinoflagellates, Alexandrium tamarense Lebour(Balech) and Gymnodinium catenatum Graham

오석진,Tamiji,윤양호 한국수산과학회 2006 Fisheries and Aquatic Sciences Vol.9 No.1

한일제약기업 연구개발비가 미래 이익에 미치는 영향

오석진,이창민 한일경상학회 2021 韓日經商論集 Vol.92 No.-

Purpose: In contrast to Korea, which introduced IFRS entirely in 2011, Japan has its own accounting standards, and in the case of IFRS, companies can arbitrarily decide to introduce IFRS from 2010. According to IFRS, R&D expenditures that satisfy the capitalization criteria are recognized as assets, but under the Japanese accounting standards, they must be treated as expenses. This paper focuses on the accounting standards for R&D expenditures, and analyzes how R&D expenditures affect future earnings. Research design, data, and methodology: The analysis subjects were selected as pharmaceutical companies with significant R&D expenditures. Accounting information of pharmaceutical companies in Korea and Japan was collected through the KIS-VALUE database and each company’s financial statements. For the analysis method, a fixed-effect model was used. Results: As a result of the analysis, different results were found in Korean companies depending on the listed market. in the case of KOSPI listed companies, capitalized R&D expenditures had a positive effect on future earnings, but in the case of non-KOSPI listed companies, it had a negative effect. Also, in a study on Japanese companies, it was confirmed that expensed R&D expenditures had a positive effect on future earnings under the Japanese accounting standards but had a negative effect when IFRS was introduced. Implications: If capitalized R&D expenditures have a positive effect on future earnings, it can consider that R&D expenditures are recognized as assets under the capitalization criteria required by IFRS. In other words, it can be said that Korean KOSPI companies met the capitalization criteria, but in the case of Non-KOSPI companies, capitalized R&D expenditures did not meet the criteria. In Japanese companies, it can be inferred that expensed R&D expenditures did not positively affect future earnings because the companies that adopted IFRS turned R&D expenditures into assets.

평행류 열교환기의 헤더부 형상 최적화

오석진,이관수 대한설비공학회 2001 설비공학 논문집 Vol.13 No.10

만족도 함수를 이용한 평행류 열교환기 설계인자 최적화

오석진 대한설비공학회 2005 설비공학 논문집 Vol.17 No.6

The heat and flow characteristics in a parallel-flow heat exchanger were examined numerically to obtain its optimal design variables. A desirability function approach was introduced to optimize its performance with respect to the design parameters over the design domain. By varying the importance of heat transfer and pressure drop which are output variables, the optimal values of the design parameters are examined. As a result, the usage of the desirability function is very effective for the optimization of the design variables in a heat exchanger since the changes of optimal values are physically appropriate by varying the importance of each output variable.

제 21 차 대한신장학회 춘계학술대회 초록집 / 포스터 발표 : Naproxen ( Naxen (R) ) 에 의한 급성 간질성 신염 1 예

오석진,김기석,김형삼,배상석,김혜영,엄재호,송형근,신향미 대한신장학회 2001 춘계학술대회 초록집 Vol.2001 No.-

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