• Biomolecules & Therapeutics
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• 제3권1호
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• pp.85-90
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• 1995

Phenol, acetaminophen (AA) and salicylamide are all known to be sulfated in rats and mice. We have previously demonstrated that capacity-limited sulfation of xenobiotics in rats is due to the reduced availability of hepatic 3'-phosphoadenosine 5'-phosphosulfate (PAPS), the cosubstrate for sulfation, which in turn is limited by the availability of its precursor, inorganic sulfate. Because species differences have been reported in the extent of sulfation, this study was conducted to determine whether these xenobiotics lower hepatic PAPS and sulfate in ICR mice. All three substrates decreased serum sulfate concentrations in a dose- and time-dependent manner. However, contrary to the observations in rats, phenol markedly increased hepatic PAPS concentrations in a dose-dependent manner, 1 hr after ip injection of 0∼4 mmol/kg. Following ip injection of 4 mmol/kg phenol, hepatic PAPS concentraions were enhanced 2∼3 fold, 0.5-2 hr after dosing and returned to control values 3 hr after dosing, whereas AA and salicylamide had little effect on hepatic PAPS concentraions. In summary, these studies demonstrate that phenol markedly enhances hepatic PAPS concentrations in mice, whereas hepatic PAPS levels are not affected by AA and salicylamide. Our data suggest that 1) hepatic sulfation for high dosages of xenobiotics in ICR mice is not limited by the availability of cosubstrate and 2) there are significant species differences in the regulation of PAPS between rats and mice.

• 분석과학
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• 제33권1호
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• pp.42-48
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• 2020

Bromate is a disinfection by-product generated mainly from the oxidation of bromide during the ozonation and disinfection process in order to remove pathogenic microorganism of drinking water, and classified as a possible human carcinogen by International Agency for Research of Cancer (IARC) and World Health Organization (WHO). For the purpose of determining the trace level concentration of bromate, several sensitive techniques are applied mostly based on suppressed conductivity detection and UV/Visible detection after postcolumn reaction (PCR). In this study, the suppressed conductivity detection method and the PCR-UV/Visible detection method through the triiodide reaction were compared to analyze the trace bromate in water samples and estimated for the availability of these analytical methods. In addtion, the state-of-the-art techniques was applied for the determination of trace level bromate in various water matrices, i.e., soft drinking water, hard drinking water, mineral water, swimming pool water, and raw water. In comparison of two analytical methods, it was found that the conductivity detection had the suitable advantage to simultaneously analyze bromate and inorganic anions, however, the bromate might not be precisely quantified due to the matrix effect especially by chloride ion. On the other hand, the trace bromate was analyzed effectively by the method of PCR-UV/Visible detection through triiodide reaction to satisfactorily minimize the matrix interference of chloride ion in various water samples, showing the good linearity and reproducibility. Furthermore, the method detection limit (MDL) and recovery were 0.161 ㎍/L and 101.0-108.1 %, respectively, with a better availability compared to conductivity detection.

• KIEE International Transactions on Electrophysics and Applications
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• 제11C권3호
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• pp.70-74
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• 2001

Admittance or impedance spectroscopy is one of the powerful tools to study dielectric relaxation and loss processes in organic and inorganic materials. In this study, the frequency dependent properties of an indium tin oxide/tris(8-hydroxyquinoline) aluminum($Alq_3$)/aluminum structure have been studied. The conductance of the $Alq_3$ film increases with the DC applied voltage up to 4V and decreases above 4V in the low frequency region. This indicates that the resistance of the device decreases with the applied bias due to the carrier injection enhancement, thereafter the injected carriers form the space charge and the additional injection of carriers is prevented. The Cole-Cole plot of the admittance takes a one-semicircle shape, which means that the device can be modeled as a parallel resistor-capacitor network. The resistance and capacitance were estimated as 8.62k${\Omega}$ and 2.7nF, respectively, at 3V in the low frequency region. The dielectric constant ( ${\epsilon}'$ ) of the $Alq_3$ film is independent of the frequency in the low frequency region below 100kHz, while the frequency dependency was observed at above 100kHz. The dielectric loss factor ( ${\epsilon}"$ ) of the $Alq_3$ film shows the dielectric dispersion below 100kHz and dielectric absorption in higher frequency domain. The dispersion is thought to be related to the hopping process of the carriers. The ${\epsilon}"$ is proportional to the reciprocal of the frequency. The dielectric relaxation time was extracted to about 0.318${\mu}s$ from the dielectric absorption spectrum.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1994년도 춘계학술대회 and 제3회 신약개발 연구발표회
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• pp.337-337
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• 1994

Phenol, acetaminophen(AA) and salicylamide are all known to be sulfated in rats and mioe. We have previously demonstrated that capacity-limited sulfation of xenobiotics in rats is due to the reduced availability of hepatic PAPS, the co-substrate for sulfation, which in turn is limited by the availability of its precursor, inorganic sulfate. Because species differences have been reported in the extent of sulfation, this study was conducted to determine whether these xenobiotics lower hepatic PAPS and sulfate in ICR mice. All three substrates decreased serum sulfate concentrations in a dose-and time-dependent manner. However. contrary to the observations in rats, phenol markedly increased hepatic PAPS concentraions in a dose-dependent manner, 1 hr after ip injection of 0-4 mmol/kg. Following ip injection of 2 or4 mmol/kg phenol, hepatic PAPS concentraions were enhanced 2-3 fold, 0.52 hr arter dosing and returned to control values 3 hr after dosing, whereas AA and salicylamide had little effect on hepatic PAPS concentrations. In summary. these studies demonstrate that phenol markedly enhances hepatic PAPS concentrations in mice, whereas hepatic PAPS levels are not affected by AA and salicylamide. Our data suggest that 1) hepatic sulfation for high dosages of xenobiotics in ICR mice is not limiod by the availability of co-substrate, and 2) there are significant species differences in the regulation of PAPS between rats and mice.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 하계학술대회 논문집 C
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• pp.1712-1714
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• 2004

During the last 20 years organic semiconductors have attracted considerable attention due to their interesting physical properties followed by various technological applications in the area of electronics and opto-electronics. It has been a long time since organic solar cells were expected as a low-cost energy-conversion device. Although practical use of them has not been achieved, technological progress continues. Morphology of the materials, organic/inorganic interface, metal cathodes, molecular packing and structural properties of the donor and acceptor layers are essential for photovoltaic response. We have fabricated solar cell devices based on zinc-phthalocyanine(ZnPc) as donor(D) and fullerine($C_{60}$) as electron acceptor(A) with doped charge transport layers, $Alq_3$ as an electron transport or injection layer. We observed the photovoltaic characteristics of the solar cell devices using the Xe lamp as a light source.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 제6회 학술대회 논문집 일렉트렛트 및 응용기술연구회
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• pp.31-34
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• 2004

During the last 20 years organic semiconductors have attracted considerable attention due to their interesting physical properties followed by various technological applications in the area of electronics and opto-electronics. It has been a long time since organic solar cells were expected as a low-cost energy-conversion device. Although practical use of them has not been achieved, technological progress continues. Morphology of the materials, organic/inorganic interface, metal cathodes, molecular packing and structural properties of the donor and acceptor layers are essential for photovoltaic response. We have fabricated solar cell devices based on zinc-phthalocyanine(ZnPc) as donor(D) and fullerine$(C_{60})$ as electron acceptor(A) with doped charge transport layers, $Alq_3$ as an electron transport or injection layer. We observed the photovoltaic characteristics of the solar celt devices using the Xe lamp as a light source.

• 대한수의학회지
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• 제29권4호
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• pp.589-599
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• 1989

A total of 13 synchronized dairy cattle(Holstein) were used to determine pregnancy rates in relation to plasma progesterone, estradiol-$17{\beta}$ levels and serum chemical values on the day of last $PGF_{2{\alpha}}$ injection and day of frozen/thawed bovine embryo transfer. The pregnancy rate of recipients with 1.0~4.0ng/ml of progesterone levels at the day of last $PGF_{2{\alpha}}$ injection was higher than that of recipients with below 1.0ng/ml or above 4.0ng/ml of progesterone levels. On the day of transfer, optimal progesterone levels were between 1.0ng/ml and 4.0ng/ml coinciding with a pregnancy rate of 88.9%. Pregnancy rate decreased when progesterone levels were below 1.0ng/ml(33.3%) or above 4.0ng/ml(0%). Corpus luteum grade did not affect pregnancy rate and this result revealed that manual palpation of corpus luteum was not valid criterion of corpus luteum function. Progesterone levels as well as pregnancy rate did not significantly differ whether the corpus luteum was on the right($1.62{\pm}1.33ng/ml$; 63.5%) or left ovary($1.99{\pm}0.61ng/ml$; 85.0%). Estradiol-$17{\beta}$ levels were not significantly different between pregnant and nonpregnant recipients, but estradiol-$17{\beta}$ levels($82.2{\pm}13.5$ VS. $72.3{\pm}10.1pg/ml$) were higher at below 1.0ng/ml of progesterone, and pregnancy rates(33.3 VS. 80%) tended to be lower than above 1.0ng/ml of progesterone. Total cholesterol levels on the day of last $PGF_{2{\alpha}}$ injection and day of transfer did not affect pregnancy rate. Calcium and inorganic phoshorus levels belonged to normal range in most of the recipients. These range did not affect pregnancy rate. In reviewing above results, plasma progesterone levels(1.0~4.0ng/ml) at the time of transfer are diagnostic value for screening recipients prior to transfer of frozen/thawed bovine embryos.

• Radiation Oncology Journal
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• 제9권1호
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• pp.1-6
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• 1991

2-ODG가 쥐의 섬유육종(FSall)에 미치는 영향에 대한 연구로 에너지 신진대사는 체내에서의 $^{31}P$-자기공명 분광기를 이용하여 관찰하였고 세포 증식 능력은 유세포 분석기를 사용하여 연구하였다. 성장속도는 10개의 세포를 $C_3Hf/Sed$ 쥐의 발등에 이식한 후 3차원적으로 측정하여 관찰하였다. 2-DDG를 투여한 경우에는 이식후 12일에 복강내로 주사하였다. 이식후 12일의 종양의 평균 크기는 $250mm^3$이었다. Fsall종양의 성장속도는 semilog graph의 기울기와 종양의 doubling time으로 측정하였다. 2-DDG를 투여한 후 성장속도가 감속되었다. 5~12일 사이의 성장속도의 기울기가 0.828, 종양의 Idubling time이 0.84일이고 대조군에서는 13~28일 사이의 기울기가 0.218, doubling time이 3.2일인 반면 2-DOG 투여군에서는 성장속도의 기울기가 0.135이고 doubling time이 5.1일이었다. $^{31}P$-자기공명 분광기를 이용하여 2-DDG의 영향을 분석해 본 결과 2-DDG 투여후 종양증식 속도의 감속과 더불어 phosphornonester (PME)와 inorganic phosphate (Pi)의증가속도가 감소하였다. 이것은 2-DDG투여후 세포의 괴사가 감소하였다는 의미가 있다. 유세포 분석기를 이용하여 종양의 증식 능력을 분석한 결과는 2-DDG 투여후 5-phase와 G2+M phase의 DNA분포가 크게 증가하였다. 이것은 2-DDG투여후 세포가 좀더 방사선에 민감한 cycle로 진행함을 의미하는 것으로 해석할 수 있다. 이에 저자들은 2-DDG가 Fsall 종양세포에 미치는 흥미있는 결과를 토대로 방사선 치료에 미치는 영향과실제 이용 가능성에 대하여 더 연구하고자 한다.

• 한국가축번식학회지
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• 제24권2호
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• pp.163-170
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• 2000

본 연구는 rBST, vitamin E 및 selenium (Se)의 투여가 한우 종모우의 혈액성분 및 호르몬의 농도변화에 미치는 영향을 검토하였다. 1. rBST 투여구, Vit. E 투여구 및 Se 투여가 한우 종모우의 혈액성분에 미치는 효과를 조사한 결과, 혈중 albumin의 함량은 Se 투여구가 대조구, rBST 투여구 및 Vit. E 투여구보다 통계적으로 유의하게 높은 함량을 나타났으며 (P＜0.05), 혼합투여구는 여타구 (대조구, rBST 투여구 및 vitamin E 투여구)보다 통계적으로 유의하게 높게 나타났다 (P＜0.05). 혈중 BUN (Blood Urea Nitrogen)과 creatinine의 함량은 rBST 투여구가 여타구보다 통계적으로 유의하게 높게 나타났다 (P＜0.05). 혈중 total protein 함량은 rBST 투여구, Se 투여구 및 혼합투여구가 대조구보다 통계적으로 유의하게 높은 함량을 나타냈다 (P＜0.05). 혈중 calcium, cholesterol, glucose, inorganic phosphoros 의 함량은 투여구간에 차이가 없었다 (P＞0.05). 2. rBST, Vit. E 및 Se 투여가 한우 종모우의 혈중내 호르몬의 변화에 미치는 효과를 조사한 결과, 혈중 estradiol의 농도는 Se 투여구와 혼합투여구가 여타구 (대조구, rBST 투여구 및 Vit. E 투여구 )보다 다소 높게 나타났지만 유의차는 인정되지 않았으며 (P＞0.05), 혈중 testeserone의 농도는 투여구간에 커다란 차이는 없었다 (P＞0.05).

• Composites Research
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• 제36권2호
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• pp.126-131
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• 2023

기존의 상용 플라스틱으로 인한 환경 오염에 대한 우려가 높아지면서 대체 재료로서 생분해성 고분자에 대한 연구가 주목을 받고 있다. 본 연구는 생분해성 열가소성 수지인 폴리 젖산에 유기 핵제의 도입으로 물성 강화 및 100% 생분해 가능한 나노복합재 개발을 목표로 한다. 그에 따라 무기 핵제의 대체재로 친환경 소재인 셀룰로오스 나노섬유를 채택하였다. 폴리 젖산 내 셀룰로오스 나노섬유의 균일한 분산을 위해 동결 건조 방식으로 나노화된 섬유 형상을 유지시켰으며, 이축압출기로 1차 교반을 진행하고, 사출 성형을 통해 이중 교반된 물성 시험용 시편을 제작하였다. 보강된 결정성을 확인하기 위해 시차주사 열량분석법을 사용하였고 1 wt%의 셀룰로오스 나노섬유가 보강재 및 핵제로서 작용하여 냉결정화온도가 약 14℃ 가량 감소하며, 결정화되는 정도 또한 증가한 것을 확인하였다. 본 연구는 기존 생분해성 고분자의 무기 핵제를 유기 나노소재로 대체함으로써 100% 생분해 가능한 친환경 나노복합재 개발하여 강화된 물성의 플라스틱 소재 개발을 위한 친환경적 대안을 제시한다.