• KSBB Journal
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• v.10 no.2
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• pp.159-165
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• 1995

Methyl fructoside was continuously produced in suspended bed enzyme reactor using alginate-enclosed microspheres biocatalyst which was developed for enzymatic synthesis of methyl fructoside. And the continuous operating conditions were optimized with reactor simulation in order to demonstrate a feasibility of commercialization of the continuous enzymatic production process development. The yield and productivity of methyl fructoside were as high as 47.1%o and $2g/\ell$-hr, respectively. The optimum operating conditions were pH 4.8, 30%(v/v) of methanol content and $2U/m\ell$ of enzyme activity when the initial concentration of sucrose is $0.291mo1/\ell$ at the reaction temperature of $25^{\circ}C$.

• Koreanishche Zeitschrift fur Deutsche Sprachwissenschaft
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• v.3
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• pp.75-94
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• 2001

Die vorliegende Arbeit versuchte durch Umfragen an die deutschen Studierenden eine statistische Untersuchung $\"{u}ber$ die Grundwortstellung des Objekts und der Adverbien des Deutschen und $\"{u}ber$ ihre $Ver\"{a}nderungsm\"{o}glichkeit$ in Bezug auf die Verbposition. Dabei wurde gezeigt, dass die Grundwortstellung je nach der Art der Adverbien variiert. Die temporalen Adverbien gehen z.B. dem Objekt vor, $w\"{a}hrend$ die lokalen Adverbien generell hinter dem Objekt stehen. Im Gegensatz zum Ergebnis von Song (1993) wurde aber fesgestellt, dass im Deutschen die Wortfolge 'Objekt + Adverb' eher die vorherrschendere ist, als die von 'Adverb + Objekt'. Hier sollte man aber klarmachen, dass man dabei fast keine absolut bevorzugte Grund­wortstellung festlegen konnte, sondem dass sie eher je nach dem Sprecher sehr variiert. Im Vergleich mit dem Koreanischen, wo die Grundwortstellung zwischen dem Objekt und Adverbien nicht schwankend ist, ist es dem Deutschen charakteristisch, dass diese Grundwortstellung je nach der Art der Adverbien variiert und auch je nach dem Sprecher schwankend ist. Die Wortstellung des Deutschen kontrastiert sich auch gegen die des Englischen, in dem das Objekt konsistent den Adverbien vorgeht. Diese Ergebnisse waren $f\"{u}r$ DaF in Korea sinnvoll, wo das Englische als die erste und das Deutsche als die zweite Fremdsprache gelehrt werden und die Lemenden im Deutschunterricht nicht nur ihre Muttersprache, sondern auch das Englische als Bezugspunkt nehmen. Durch die Umfragen hat es sich nun ergeben, dass die Grund­wortstellung des Deutschen auch mit der Verbposition $zusammenh\"{a}ngt$. D.h., im Deutschen, wo das Verb an der zweiten Stelle oder am Ende des Satzes vorkommen kann, kann die Wortstellung von der Verbposition beeinflusst werden. Unter den verbfinalen Strukturen zeigt sich in den $Nebens\"{a}tzen\;die\;M\"{o}glichkeit\;der\;Wortfolgever\"{a}nderung$ deutlicher als in den $Modalverbs\"{a}tzen$ oder in den perfektiven$S\"{a}tzen$.

• Journal of the Korean Magnetics Society
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• v.16 no.6
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• pp.276-278
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• 2006

The switching characteristics of magnetic tunnel junctions (MTJs) comprising amorphous ferromagnetic CoFeSiB free layer have been investigated. CoFeSiB was used for the free layer to enhance the switching characteristics. The typical junction structure was $Si/SiO_{2}/Ta$ 45/Ru 9.5/IrMn 10/CoFe $7/AlO_{x}/CoFeSiB\;(t)/Ru\;60\;(in\;nm)$. CoFeSiB has low saturation magnetization ($M_{s}$) of $560\;emu/cm^{3}$ and high anisotropy constant ($K_{u}$) of $2800\;erg/cm^{3}$. These properties caused low coercivity ($H_{c}$) and high sensitivity in MTJs, and it also confirmed in submicrometer-sized elements by micromagnetic simulation based on the Landau-Lisfschitz-Gilbert equation. By increasing CoFeSiB free layer thickness, the switching characteristics became worse due to increase of the demagnetization field.

• Korean Journal of Clinical Laboratory Science
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• v.47 no.4
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• pp.273-278
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• 2015

The purpose of this study was to evaluate the in-vitro efficacy of PDT using red light emitting diode (LED) with Radachlorin for biofilm inhibition of clinical Candida albicans isolates. The suspensions containing C. albicans at $9{\times}10^8CFU/mL$ were prepared on yeast nitrogen base containing 5% glucose. The biofilm formation was grown for 3 h after seeding suspensions each 100 ul on a 96-well plate and then supernatant was discarded. Each well was treated with $0.39{\mu}g/mL$ from $50{\mu}g/mL$ concentrations of Radachlorin on adherent biofilm. After a 30-minute incubation, light was irradiated for 30, 60, or 90 minutes using the following light source of wavelength 630 nm LED, at energy densities of 14, 29, and $43J/cm^2$. Afterwards, all supernatant was removed and dried. Adherent cells were stained with safranin O and dried. The cell viability was measured using a microplate reader at 490 nm. Also, a fluorescent signal on C. albicans was observed by saturation of a photosensitizer. In conclusion, a significant inhibition of 72.5% was observed to C. albicans on biofilm at the Radachlorin dose of $50{\mu}g/mL$ with 630 nm LED. The Photosensitizer (Radachlorin) was adequate at 30 minuttes for C. albicans. Overall, the results showed that inhibition of biofilm formation was Radachlorine dose-dependent. The results suggest that PDT, using Radachlorin with 630 nm LED, is able to decrease biofilm formation of C. albicans.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.729-736
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• 2007

The objective of this study was to investigate the anti-oxidative effects of pyruvate, taurine and melatonin on sperm characteristics(motility, membrane integrity) and lipid peroxidation(LPO) for in vitro storage of boar semen. Semen was treated with various antioxidants such as pyruvate(1mM), taurine(50mM) and melatonin(100nM) with or without 100uM H2O2. Antioxidant treatments were significantly increased the sperm motility when compare to control group in all incubation periods(P≤0.05). Hypoosmotic swelling test(HOST), membrane integrity was similar to the result of motility. In lipid peroxidation measurement by TBA reactions of spermatozoal plasma membrane, malondialdehyde(MDA) level in control and antioxidant treatments were lower than those of antioxidant plus H2O2 or H2O2 treatment for 3 to 6 h incubation period. Relationships of evaluation methods for sperm viability were investigated by motility, membrane integrity and lipid peroxidation. Among evaluation methods, LPO vs motility and membrane integrity vs LPO were negatively correlated(－0.23~－0.92 and －0.68~－0.85), but membrane integrity vs motility was positively correlated (0.53~0.94) in all treatments. These experiments indicate that supplementation of antioxidant to the semen extender can increase the sperm motility and membrane integrity and decrease the lipid peroxidation of spermatozoal plasma membrane. The HOST might be utilized to evaluate the sperm quality instead of lipid peroxidation or motility.

• Journal of the Society of Naval Architects of Korea
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• v.37 no.2
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• pp.100-108
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• 2000

As U.S. congress and I.M.O. have recently adopted strengthened MARPOL73/78 regulations on marine pollution, it is necessary to develope a new type of tankers such as Double hull tanker(D/H Tanker) and Mid-deck tanker(M/D Tanker) and so on. Because most of researches are concentrated on the volume of oil spill due to collision of ships, in this paper, a structural design program for D/H Tankers and M/D Tankers is developed to suggest the effective type of tankers by comparing structural characteristics between their types. By this program, minimum hull weight designs of D/H tankers and M/D tankers considering tank arrangement are performed and the design results are compared each other. The efficient types of hull structure for the minimum weight design between D/H tankers and M/D tankers is proposed.

• ALGAE
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• v.25 no.3
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• pp.133-140
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• 2010

Using chlorophyll fluorescence, the vertical migration of benthic diatoms responding to light intensity and affected by sediment grain size was studied. Minimal fluorescence ($F_o$) of surface sediment was measured by imaging pulse amplitude modulated (Imaging-PAM) fluorometer, and used to monitor diatom biomass variation in surface sediments. The test diatoms, Amphora coffeaeformis (C. Agardh) K$\ddot{u}$tzing and Cylindrotheca closterium (Ehrenberg) Reimann & Lewin, migrated to the sediment surface under irradiance from 50 to 500 ${\mu}mol$ photons $m^{-2}s^{-1}$. However, the diatoms exhibited no evident increase of surface biomass under dark conditions, and even showed slightly decrease of surface biomass under irradiances over 1,000 ${\mu}mol$ photons $m^{-2}s^{-1}$. The light intensity inducing the maximum surface migration of A. coffeaeformis was 100 ${\mu}mol$ photons $m^{-2}s^{-1}$, while the light intensity producing the same effect for C. closterium was 250 ${\mu}mol$ photons $m^{-2}s^{-1}$. C. closterium showed higher motility than A. coffeaeformis. Faster diatom surfacing was observed in larger grain size sediments (125-335 ${\mu}m$) than smaller ones (63-125 ${\mu}m$). This study confirmed the significant influence of light as a main triggering factor behind migration, indicated the distinct effect of different sediment grain size, and highlighted the species-specific migratory ability.

• Proceedings of the Korean Vacuum Society Conference
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• 2014.02a
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• pp.420-420
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• 2014

최근, 과학 기술이 발달함에 따라 현장에서의 실시간 검사 및 자가 지단 등 질병 치유에 대한 사람들의 관심이 증가하고 있으며, 이에 따라 의료, 환경, 산업과 같은 많은 분야에서 바이오 센서에 대한 연구가 활발하게 이루어지고 있다. 그 중, EGFET는 전해질 속의 각종 이온 농도를 전기적으로 측정하는 바이오 센서로, 외부 환경으로부터 안전하고, 제작이 쉬우며, 재활용이 가능하여 비용을 절감 할 수 있다는 장점을 가지고 있다 [1]. EGFET는 감지부와 FET부로 분리된 구조를 가지고 있으며, 감지부의 감지막으로는 Al2O3, HfO2, $TiO_2$, SnO2 와 같은 다양한 물질들이 사용되고 있다. 그 중, SnO2는 우수한 감도와 안정성을 가지고 있는 물질로 추가적인 열처리 공정 없이도 우수한 감지 특성을 나타내기 때문에 본 연구에서 감지막으로 사용하였다. 한편, EGFETs 의 FET부로는 기존의 비정질 실리콘 TFTs 에 비해 10배 이상의 높은 이동도와 온/오프 전류비를 갖는 InGaZnO 를 채널층으로 사용한 TFTs 를 사용하였다. a-IGZO 는 넓은 밴드 갭으로 인해 가시광 영역에서 투명하며, 향후 투명 바이오센서 제작 시, 물질들 사이의 반응을 전기적 신호뿐만 아니라 광학적인 분석 방법으로도 검출이 가능하기에 고 신뢰성을 갖는 센서의 제작이 가능할 것으로 기대된다. 한편, a-IGZO TFTs 의 경우 우수한 전기적 특성을 나타냄에도 불구하고 소자 동작 시 문턱 전압이 불안정하다는 단점이 있으며 [2], 이러한 문제의 개선과 향후 투명 기판 위에서의 소자 제작을 위해서는 저온 열처리 공정이 필수적이다. 따라서, 본 연구에서는 저온 열처리 공정인 u-wave 열처리를 통하여 a-IGZO TFTs 의 전기적 특성 및 안정성을 향상시켰으며, 9.51 [$cm2/V{\cdot}s$]의 이동도와 135 [mV/dec] 의 SS값, 0.99 [V]의 문턱 전압, 1.18E+08의 온/오프 전류 비를 갖는 고성능 스위칭 TFTs 를 제작하였다. 최종적으로, 제작된 a-IGZO TFTs 를 SnO2 감지막을 갖는 EGFETs 에 적용함으로써 우수한 감지 특성과 안정성을 갖는 바이오 센서를 제작하였다.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.74-74
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• 2002

Production of u 1-antitrypsin ($\alpha$AT) in transgenic cows has a great value in the field of medicine. The present study was conducted to determine the effect of chemically defined KSOM media on in vitro development of bovine transgenic nuclear transfer (NT) embryos. An expression plasmid for human $\alpha$AT was constructed by inserting a bovine beta-casein promoter, a green fluorescent protein (GFP) marker gene, and a human $\alpha$AT target gene into a pcDNA3 plasmid. Cumulus cells as donor nuclei in NT were collected from a Holstein cow and transfected by lipid-mediated method using FuGene6 (Roche Molecular Biochemicals, USA) as reagent. GFP expressed cumulus cells were introduced into recipient oocytes under DIC microscopy equipped with FITC filter set. After electrical fusion and chemical activation, reconstructed embryos were cultured in 1) SOF + 0.8% BSA, 2) KSOM + 0.8% BSA, 3) KSOM + 10% FBS and 4) KSOM +0.01% PVA for 192 h at 39$^{\circ}C$ with 5% $CO_2$, 5% $O_2$ and 90% $N_2$in humidified condition. The development of the embryos was recorded and the GFP expression in blastocyst was determined under FITC filter. The average fusion rate was 73.8% (251/340; n=8). The development rates to 2-4 cells, morula, blastocysts and expression rates in blastocysts varied from 70.3 to 76.5%, 30.2 to 33.8%, 25.4 to 33.8% and 11.8 to 15.6%, respectively. The difference in development and expression rates of embryos among 4 culture groups was not significant (P>0.05). This study indicates that chemically defined KSOM medium is also able to support development of bovine transgenic NT embryos at similar rate of SOF or KSOM supplemented with BSA or serum.

• Korean Journal of Soil Science and Fertilizer
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• v.21 no.2
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• pp.129-134
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• 1988

Enzymatical properties of Streptomyces sp. S-45 producing chitinase and ${\beta}$-1.3-glucanase isolated from soil were investigated. Chitinase activity was 3.01(U/ml) and ${\beta}$-1.3-glucanase activity was 2.49(U/ml). The optimum medium for mycolytic enzyme production of strain was composed of 0.7% colloidal chitin, 0.3% glucose, 0.5% asparagine, 0.2% peptone, 0.01% NaCl, 0.01% $K_2HPO_4$ and 0.01% $MgSO_4{\cdot}7H_2O$ in intial pH 7.0. The optimal condition for mycolytic enzyme activities were: pH 6.5-7.0, $45-50^{\circ}C$. Enzyme activities were activated by metal ion as $10^{-2}M\;Co^{{+}{+}}$, $Cu^{{+}{+}}$, $Mn^{{+}{+}}$, $Al^{{+}{+}{+}}$ and $10^{-3}M\;Sn^{{+}{+}}$ but $Ag^{{+}{+}}$, $Hg^{{+}{+}}$ inhibited.