• Journal of Food Hygiene and Safety
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• v.11 no.1
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• pp.71-75
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• 1996

In order to study the antitumoral effect of Selaginella tamariscina extracts, the cytotoxicities to human histiocytic leukemia cells (U937) and lymphocyte were measured by MTT method. The water extract of Selaginella tamariscina was partitioned into chloroform (CHCl3), ethylacetate (EtAc), n-butanol (BuOH) and water (H2O), successively. CHCl3, EtAc and BuOH fractions of Selaginella tamariscina showed the cytotoxicity to the U937 cells but they had effect on the cytotoxicity of lymphocyte under the same conditions. The tumor-specific cytotoxicity of Selaginella tamariscina fractions migh have been attributed to their genotoxic effect on actively proliferating cells. The expression of p53 tumor suppressor gene was then evaluated by northern blotting. The increased expression of p53 was induced by Selaginella tamariscina fraction V but no expression of p53 was induced by CHCl3, EtAc, and BuOH fractions of Selaginella tamariscina water extract (fraction V) should be required for the cytotoxcity on U937 and the other fractions of Selaginella tamariscina mediated the U937 disruption.

• Journal of the Korean Mathematical Society
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• v.43 no.5
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• pp.1099-1114
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• 2006

Relations between closure-type properties of hyperspaces over a $\v{C}ech$ closure space (X, u) and covering properties of (X, u) are investigated.

• Korean Journal of Microbiology
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• v.17 no.4
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• pp.193-197
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• 1979

Attempts were made to elucidate the process of biodegradation of furfural. Zoogloea sp. isolated from soil could convert furfural into 2-furoic acid by a certain enzyme (s) and also accumulated it extracellularly. This substance was extracted with diethyl ether and identified with U.V. spectrophotometry, high pressure liquid chromatography (HPLC) and IR spectrophotometry.

• Proceedings of the Korea Contents Association Conference
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• 2013.05a
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• pp.133-134
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• 2013

현재 세계문화유산 등재 추진 중에 있는 전국 서원 6개소 조경유적의 구성요소를 도출하고, 이를 기초로 식물유산과 관련하여 진정성 평가항목 7가지에 부합하는 사례를 분석한다. 이를 통하여 과연 유산으로 등재될 만한 가치를 지니고 있는지 판단 여부에 대한 기초정보를 제공하고자 한다.

• The Pure and Applied Mathematics
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• v.2 no.2
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• pp.141-148
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• 1995

In this paper we shall consider function p(z) analytic in the open unit circle D and the solutions y(z) of the differential equation y"(Z) ＋ p(z)y(z) = 0. (1.1) The ratio f(z) = u(z)/v(z) of any two independent solutions u(z) and v(z) of (1.1) will be function f(z), meromorphic in D with only simple poles, and such that f'(z) (equation omitted) 0. We shall say that a meromorphic function which satisfies these two condition belongs to the restricted class.(omitted)

• The Korean Journal of Ecology
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• v.16 no.4
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• pp.429-438
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• 1993

This is a report on the early vegetation and the secondary succession in the burned area of SeobJe-Go1 of $IIwasan-MY\v{o}n,\;Y\v{o}ngch\v{o}n-Gun,\;Ky\v{u}ngsangbuk-do$ Province. The forest fire occurred on April 8, 1982 and the pine forest and its floor vegetation were burned down. The investigation was done six times from August 20, 1982 to August 13, 1983. The results are summarized as follows: the floristic composition of burned areas $B_1,\;B_2$, and unburned areas $U_1,\;U_2$ were composed of 25, 23, 32, and 27 kinds of vascular plants. respectively. The biological spectra showed the $H-D_1-R_5-e$ type in both the burned and unburned areas. The species of Arundinella hirta, Miscanthus simnsis var. purpurascens and Cares hurnilis var. nana were dominant species in the burned area, while Pinus densiflorrr, Corex humilis var. nana and Rhododendron mucronulatum var. ciliafum were dominant species in the unburned area. Degree of succession of the unburned area was comparatively higher than that of the burned area. Species diversity index and evenness index of the burned area were similar to those of the unburned area. Indices of similarity in sampling sites showed that $B_1\;and\;B_2$ stands were the most similar. pH, total nitrogen, available phosphorus and exchangeable potassium of soil increased but organic matter and total organic carbon decreased after fire.

• The Korean Journal of Pharmacology
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• v.16 no.2 s.27
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• pp.9-14
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• 1980

The influence of penicillin G infusion(7.5 units/min/kg) on the diuretic action of furosemide$(250{\mu}g/kg)$ in rabbits was studied to investigate the drug interaction between penicillin G and furosemide. The results were as follows: 1) There was no significant change in renal function in the penicillin G infused rabbits compared with the normal ratbit. 2) In comparison with the control group, a significant increase in ${\triangle}U_{flow},\;{\triangle}U_{Na}V,\;{\triangle}U-kV\;and{\triangle}U_{cl}V$ was noted by 30 minutes following the administration of furosemide in the penicillin G infused group. There was no significant difference in ${\triangle}C_{In},\;{\triangle}C_{PAH}$ between the two groups and ${\triangle}Na^+$ reabsorption rate was significantly decreased in the latter. The potentiating effect of penicillin G on the diuretic action of furosemide should be due to the increased luminal concentration of free form of furosemide, and it may be related to the competitive inhibition of plasma protein binding between the two drugs.

• Proceedings of the IEEK Conference
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• 2004.06b
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• pp.509-512
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• 2004

This paper proposed a new solid State Relay(SSR) structure that can replace the conventional SSR as a power IC. The photodiode arrays, the main part of this structure, were designed and integrated in the same power It chip with the output parts, LDMOSFET and BJT, on a SOI substrate. The fabrication of this input part shared the same output LDMOSFET fabrication processs, except the additional deposition of Silicon nitride($Si_3N_4$) for the photo-detection part. According to LED illumination intensites and photo detecting areas, we could obtain voltage of 0.49V ${\~}$0.52V and current of 5.5uA ${\~}$ 108uA respectively from the fabricated unit photodiode. The maximum value of the voltage and the current we could obtain from the photodiode array were 3.58V and 24.4uA respectively, and the voltage was enough to operate the output LDMOSFET

• Transactions on Electrical and Electronic Materials
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• v.15 no.6
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• pp.315-319
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• 2014

In this paper, we investigate visible light stress instability in radio frequency (RF) sputtered a-IGZO thin film transistors (TFTs). The oxygen flow rate differs during deposition to control the concentration of oxygen vacancies, which is confirmed via RT PL. A negative shift is observed in the threshold voltage ($V_{TH}$) under illumination with/without the gate bias, and the amount of shift in $V_{TH}$ is proportional to the concentration of oxygen vacancies. This can be explained to be consistent with the ionization oxygen vacancy model where the instability in $V_{TH}$ under illumination is caused by the increase in the channel conductivity by electrons that are photo-generated from oxygen vacancies, and it is maintained after the illumination is removed due to the negative-U center properties.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2002.09a
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• pp.94-96
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• 2002

In order to achieve the radiotherapy more precisely using highly energetic heavy charged particles, it is important to know the distribution of the electron density in a human body, which is highly related to the range of charged particles. We can directly obtain the 2-D distribution of the electron density in a sample from a heavy ion CT image. For this purpose, we have developed a heavy ion CT system using a broad beam. The performance, especially the position resolution, of this system is estimated in this work. All experiments were carried out using the heavy ion beam from the HIMAC. We have obtained the projection data of polyethylene samples with various sizes using He 150 MeV/u, C 290 MeV/u and Ne 400 MeV/u beams. The used targets are the cylinders of 40, 60 and 80 mm in diameter, each of them has a hole of 10 mm in diameter at the center of it. The dependence of the spatial resolution on the target size and the kinds of beams will be discussed.