• Applied Biological Chemistry
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• 제25권3호
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• pp.155-160
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• 1982

Claviceps spp.는 tryptophan함유배지에서 적갈색 색소를 형성한다. D.L.-tryptophan$[side\;chain-3^{14}C]$를 배지에 첨가하였을 때 $^{14}C-labeled$ pigment와 constant specific radioactivity를 갖는 5-hydroxytryptophan을 재결정 분리하였다. 동시에 $^{14}C-labeled$ 5-hydroxytryptophan으로 같은 실험을 행한 결과, tryptophan 보다 4배 이상, 색소물질로 주입되는 것을 관찰할 수 있었다. 한편, UV-spectrum 및 fluorometric analysis등에 의하여 배지중 5-hydroxytryptophan이 생합성되는 것을 확인할 수 있었다. tryptophan에서 출발하는 또 하나의 ergot pigment 생합성경로는 곰팡이 생육배지중에서 40pmde/mg protein 농도의 cytochrome p-450을 분리 정제할 수 있어 tryptophan이 hydroxylation되어 5-hydroytryptophan으로 전환하는 효소학적 반응으로 검정되어 hydroxylation반응이 우선하는 기작에 의한 것임을 알 수 있다.

• 약학회지
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• 제39권6호
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• pp.577-584
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• 1995

On the combination of antacid, the pharmacokinetics and gastric adhesion of [$^{14}c$]aceglutamide aluminium complex([$^{14}C$]AGA) were examined in rats. Specially, this study was focused on the drug interaction that the co-administration of antacid may affect the oral absorption and gastric adhesion of aceglutamide aluminium complex(AGA). In the study of the oral co-administration of [$^{14}C$] AGA and antacid(aluminium hydroxide and magnesium hydroxide(AM)), the radioactivity of plasma and urinary recovery was lower than that of [$^{14}C$]AGA alone administered group. However, the cumulative recovery of radioactivity in feces was increased significantly. The comparative bioavailability of [$^{14}C$] AGA from the plasma concentration-time curve and urinary recovery was about 60%. In vitro, the effect of antacid on the gastric adhesion of AGA was not significatly different between AGA and AGA/antacid treatment. And it accorded well with the result of in vivo experiment. In conclusion, on the combination of antacid, the oral absorption of AGA was decreased by the gastric adhesion was not affected in respect of drug interaction.

• 방사성폐기물학회지
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• 제18권4호
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• pp.439-455
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• 2020

Numerical model was developed that simulates radionuclide (3H and 14C) transport modeling at the 2nd phase facility at the Wolsong LILW Disposal Center. Four scenarios were simulated with different assumptions about the integrity of the components of the barrier system. For the design case, the multi-barrier system was shown to be effective in diverting infiltration water around the vaults containing radioactive waste. Nevertheless, the volatile radionuclide 14C migrates outside the containment system and through the unsaturated zone, driven by gas diffusion. 3H is largely contained within the vaults where it decays, with small amounts being flushed out in the liquid state. Various scenarios were examined in which the integrity of the cover barrier system or that of the concrete were compromised. In the absence of any engineered barriers, 3H is washed out to the water table within the first 20 years. The release of 14C by gas diffusion is suppressed if percolation fluxes through the facility are high after a cover failure. However, the high fluxes lead to advective transport of 14C dissolved in the liquid state. The concrete container is an effective barrier, with approximately the same effectiveness as the cover.

• Ocean and Polar Research
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• 제44권1호
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• pp.99-111
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• 2022

Together with the development of measurement techniques, radiocarbon (¹⁴C) has been increasingly used as a key tool to investigate carbon cycling and associated biogeochemistry in the ocean. In this paper, the current status of radiocarbon studies in the East Sea (Japan Sea) is reviewed. Previously, spatiotemporal distribution and change of the water masses in the East Sea from 1979 to 1999 were investigated by using the ¹⁴C in the dissolved inorganic carbon (DIC). Researches on sinking particulate organic carbon (POC) revealed that POC in the deep ocean has more complex and heterogeneous origins than we expected. In particular, since 2011, Korean researchers have been collecting sinking particle samples for more than 10 years, so it is expected that ¹⁴C of POC will provide important information to understand carbon cycling in relation to climate change. Although the quantity of ¹⁴C data published in the East Sea is still limited, the importance and the future direction of using ¹⁴C to understand the biogeochemical mechanisms of carbon cycling and its role as a carbon reservoir in the East Sea are detailed herein.

• Applied Biological Chemistry
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• 제42권3호
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• pp.229-234
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• 1999

사람 간세포 유래의 배양 세포인 HepG2 세포의 지질 합성과 분비에 미치는 linoleic acid(LA, 18 : 2 n-6) 및 우혈청알부민 (bovine serum albumin: BSA) 첨가 농도의 영향에 대하여 검토하였다. 간세포는 DMEM배지(기본 배지)에 0.2 mM LA을 첨가한 배지 및 LA와 BSA(0.2-1.0%)를 첨가한 배지(LA+BSA 배지)에서 배양하였다. 각 지질의 동위원소 표적에는 $[^{14}C]acetate$를 이용하여 6시간 배양후의 지질합성과 분비를 측정하였다. 그 결과, 기본 배지중에 LA의 첨가는 콜레스테롤의 $[^{14}C]acetate$ 표적량을 저하 시켰다. 한편, LA배지에 BSA의 첨가에 의해, 총 콜레스테롤의 $[^{14}C]acetate$ 표적량은 증가하는 경향을 나타내었다. LA+BSA 배지에서 간세포의 총 콜레스테롤 변동은 유리형 콜레스테롤에의 표적량 증가에 기인하는 것으로 나타났다. LA배지에 BSA를 첨가 하였을때 콜레스테롤 분비가 증가 하였는데, 이는 지질의 분비과정에 BSA가 관여하는 것을 시사하는 것이다. 간세포내 총 지질에의 $[^{14}C]acetate$ 표적량은 각 군간의 유의치는 인정되지 않았다. 그러나, LA 배지에의 BSA 첨가는 $[^{14}C]acetate$표식 지방산의 중성지질 획분에의 표적량은 증가하고, 인지질 획분에 표적량은 감소하여, 양지질의 합성에는 상반되는 결과를 나타내었다. $[^{14}C]acetate$ 표적 중성지질, 인지질 및 유리지방산의 분비는 LA배지에 비교해 LA+BSA 배지에서 현저하게 증가하였다. 이상의 결과에서, 사람 간배양 세포에서 LA와 BSA는 각각 지질대사에 다른 영향을 미치고, BSA 농도는 리포단백질 분비에 영향을 미치는 것으로 시사된다.

• 한국동물학회지
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• 제29권2호
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• pp.79-85
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• 1986

생쥐난자내에 cAMP phosphodiesterase(PDE)가 존재하는 가를 확인하고 cAMP PDE와 난자성숙간의 관계를 밝히기 위해 본 실험을 행하였다. 실험결과 생쥐난자내에는 Michaelis 상수 (Km)와 반응 최대속도 (Vmax)가 다른 두종의 cAMP PDE가 있다는 것이 밝혀졌다. 즉 하나는 Km 값이 $0.14 \\pm 0.01 \\muM$ 이고 Vmax 값이 $0.42 \\pm 0.07$ fmol cAMP hydrolyzed/oocyte/minute이고, 다른 하나는 Km 값이 $14.5 \\pm 2.0 \\muM$ 이고 Vmax 값이 $2.2 \\pm 0.5$ fmol cAMP hydrolyzed/oocyte/minute이다. 또한 PDE의 cAMP 분해작용은 난자성숙 억제제로 알려진 theophylline과 isobutyl-methylxanthine에 의해 저해되었으나 그 작용은 가역적이었다. 이 실험결과는 PDE의 활성저해로 인한 난자내의 cAMP의 축적이 결국 난자성숙을 억제하고 있다는 것을 암시하고 있다.

• Asian-Australasian Journal of Animal Sciences
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• 제13권9호
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• pp.1285-1289
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• 2000

This study investigated the lipogenesis capacity of hepatocytes and lipolysis rate of adipocytes of broilers as affected by different fatty acids (trial one) and different linoleic acid (C18:2) levels (trial two). Twenty 6-wk old broilers were used; their hepatocytes and adipocytes were isolated for the in vitro study. In trial one, four treatments were tested. The control group in which no fatty acid was added, and the test groups to which were added $300{\mu}M$ of C16:0, C18:1 and C18:2, respectively. For trial two, different levels (0, $300{\mu}M$ and 1 mM) of C18:2 combined to fatty acid-free bovine serum albumin (BSA) were added to the medium. According to results of trial one, added fatty acids significantly reduced the incorporation by hepatocytes of [U,$^{14}C$]glucose into total lipid (p<0.05); the lipogenesis capacity in C18:2 group was the lowest. Although a similar pattern was found with [l,$^{14}C$]acetate, the groups only slightly differed in terms of lipogenesis capacity (p=0.11). In addition, the C18:2 group had a significantly (p<0.05) greater lipolysis rate than the C16:0 and control groups. Results of trial two indicated that C18:2 significantly (p<0.05) reduced lipogenesis capacity both for [U,$^{14}C$]glucose and [l,$^{14}C$]acetate, and markedly stimulated the lipolysis rate (p<0.05), displaying a dose response. Results presented herein demonstrate that C18:2 can reduce lipogenesis capacity and stimulate the lipolysis rate in broilers.

• Restorative Dentistry and Endodontics
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• 제5권1호
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• pp.29-34
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• 1979

The purpose of this study was to measure thermal expansions of dental investments, Biovest(Casting Investment. Dentsply International INC, U.S.A.), Multi-Best (Use for all dental chrome-cobalt alloys, The Ransom & Randolph Co. U.S.A.), Kerr(Inlay Investment. Sybron Kerr, U.S.A.), O. K. (Inlay Investment. Shofu Dental MFG, Co. Japan), Whip-Mix (Cristobalite Inlay Investment. Whip-Mix Corporation. U.S.A.). Thermal expansion of specimens(5mm in diameter and 50mm in length) was measured by a dilatometer at the temperature range from $20^{\circ}C$ to $700^{\circ}C$ by comparing expansion between standardized quartz and experimental specimens with heating rate about $300^{\circ}C$/hr. The following results were obtained. 1. The coefficient of thermal expansion of Biovest was $15{\times}10^{-6}/^{\circ}C$ in the water powder ratio 18/100 and $14{\times}10^{-6}/^{\circ}C$ in the water powder ratio 28/100. Those of Multi-Best were $9{\times}10^{-6}/^{\circ}C$ in the water powder ratio 14/100 and $7{\times}10^{-6}/^{\circ}C$ in the water powder ratio 24/100. 2. The coefficient of thermal expansion of Kerr were $17{\times}10^{-6}/^{\circ}C$ in the water powder ratio 38/100 and $14{\times}10^{-6}/^{\circ}c$ in the water powder ratio 48/100. Those of O. K. were $9{\times}10^{-6}/^{\circ}C$ in the water powder ratio 33/100 and $7{\times}10^{-6}/^{\circ}C$ in the water powder ratio 43/100 3. The coefficient of thermal expansion of Whip-Mix were $14{\times}10^{-6}/^{\circ}C$ in the water powder ritio 40/100 and $12{\times}10^{-6}/^{\circ}c$ Fein the water powder ratio 50/100. Those of Hi-Heat were $11{\times}10^{-6}/^{\circ}c$ in the water powder ratio 28/100 and $10{\times}10^{-6}/^{\circ}c$ in the water powder ratio 38/100.

• 한국잡초학회지
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• 제4권2호
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• pp.125-129
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• 1984

본(本) 실험(實驗)은 올방개, 가래, 율미를 공시(供試)하여 토양온도구배장치(土壤溫度勾配裝置)(Daiki-830)를 이용(利用)하여 토양온도(土壤溫度)를 10, 14, 18, 22, 26, $30^{\circ}C$로 처리(處理)하여 출아상태(出芽狀態)와 초기생장(初期生長)을 조사(調査)하였다. 1. 올방개는 토양온도(土壤溫度) $14^{\circ}C$ 이상(以上)에서 출아(出芽)가 시작 되었으며 $26^{\circ}C$에서 출아율(出芽率)이 가장 높았고 $30^{\circ}C$는 발아율(發芽率)이 다소 감소(減少)되었다. 2. 가래의 출아율(出芽率)은 토양온도(土壤溫度) $10^{\circ}C$에서 매우 낮았고 $14^{\circ}C$ 이상(以上)의 온도(溫度)에서 출아율(出芽率)이 높았으며 온도가 높아짐에 따라 출아속도(出芽速度)가 빨랐다. 3. 올미의 출아율(出芽率)은 파종후(播種後) 10일(日)까지 토양온도(土壤溫度)가 높아짐에 따라 증가(增加)하였으며 모든 토양온도(土壤溫度)에서 최종출아율(最終出芽率)은 100%를 나타내었다. 4. 토양온도(土壤溫度)가 올라감에 따라 모든 공시(供試) 초종(草種)에서 80%출아(出芽) 소요일수(所要日收)는 크게 단축(短縮)되었으며 올미는 비교적 짧았으나 가래는 긴편이었고 올방개는 가장 길었다. 5. 출아(出芽)까지의 적산토양온도(積算土壤溫度)는 올방개가 가장 높고 가래, 올미 순(順)으로 낮았다. 6. 올방개, 가래, 올미의 초기생장(初期生長) 최적온도(最適溫度)는 올방개 $26^{\circ}C$, 가래 $18\sim22^{\circ}C$, 올미는 $18\sim26^{\circ}C$이었다.

• 한국주조공학회지
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• 제4권4호
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• pp.30-33
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• 1984

Nitrogen solubility in liquid Fe and Fe-C alloys has been measured by the levitation melting method under 1 atm $N_2$ pressure. Experiments were carried out at the temperature range of $1774-2097^{\circ}K$ and carbon content of 0-5.06wt%. The nitrogen solubilities measured in pure Fe and Fe-C alloys were $log(wt%N)_{Fe}=-424/T-1.129$ and $log(wt%N)_{Fe-C}=-[424/T+1.129+(%C)/19.14{5447/T-0.612}+(%C)^2/19.14$ 2478/T-1.265].