• Title/Summary/Keyword: Kr-85

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High-performance liquid chromatographic assay and oral pharmacokinetics of new anti-HIV uracil derivatives, KR-V analogues, in rats

  • Lee, Youngmi;Heeok Shim;Seoungryong Yu;Hochul Shin;Moonkoo Chung;Jungkoo Roh
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1998.11a
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    • pp.123-123
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    • 1998
  • A number of uracil derivatives have been developed as anti-AIDS drugs having a mechanism of inhibiting cellular reverse transcriptase. A simple and rapid assay technique for recently synthesized KR-V analogues was developed using a high-performance liquid chromatography, and oral pharmacokinetics was examined for assessing their oral bioavailabilites. Plasma samples were analyzed by reversed-phase HPLC using an ODS column with an ultraviolet detection system. All the analogues were eluted within 12 min and the LOQ was 15-30 ng/$m\ell$. The extraction recoveries were higher than 85%, except KR-V1039, 1068 and 1720 having ester group. This chromatic method was well applied to the kinetic studies for KR-V analogues. Among 16 analogues tested in the present work, the 6 compounds including KR-V1123, 1122, 1784, 1783, 1736 and 1700 were found to be bioavailable for oral administration to rats.

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A geometrical study of karst landforms (Karst landforms 의 지구화학적 연구)

  • 유재신
    • Proceedings of the Speleological Society Conference
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    • 1994.11a
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    • pp.84-85
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    • 1994
  • 카르스트란 용어는 원내 Slav어인 Krs에서 유내된 말인데 울퉁불퉁한 암석이나 일반적으로 암석이란 뜻이며 Yugoslavia의 서북부 Slovenia 지방에 분포하고 있는 석회암지대를 가르키며 독일어인 "Karst"란 용어가 전세계적으로 통용되고 있다.(중략)

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Cloning and Characterization of cDNA for Korean Rockfish (Sebastes schlegeli ) Insulin-like Growth Factor-I

  • Kwon, Mi-Jin;Jo, Jae-Yoon;Nam, Taek-Jeong
    • Journal of Marine Bioscience and Biotechnology
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    • v.1 no.2
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    • pp.119-125
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    • 2006
  • To understand the comprehensive mechanisms of biological function for insulin-like growth factor-I (IGF-I) in vertebrates, we have investigated the cDNA sequence of this gene in the korean rockfish (Sebastes schlegeli). The mature form of korean rockfish IGF-I was found to be comprised of 67 amino acid residues, showing about a 7 kDa molecular weight. In this study, we used the polymerase chain reaction (PCR) to obtain a korean rockfish IGF-I (KR IGF-I) cDNA fragment, and methods of rapid amplification of cDNA ends (RACE) to obtain a full length of the KR IGF-I sequence. The KR IGF-I encoded for a predicted amino acid sequence showed identities of 93.6 %, 90.7 %, and 85.4 % in comparison with flounder, chinook salmon, and human IGF-I, respectively. To obtain recombinant biologically active polypeptides, korean rockfish B-C-A-D domains were amplified using the PCR, then the isolated cDNA was expressed in the E. coli BL21(DE3). The recombinant KR IGF-I protein biological function was measured by stimulation of [$^3H$] thymidine incorporation, suggesting the cDNA codes for the korean rockfish proIGF-I.

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Protective effect of KR-32000 against hypoxia- and oxidative stress-induced cardiac cell death

  • Kim, Mi-Jeong;Yoo, Sung-Eun;Yi, Kiu-Yang;Lee, Sun-Kyung;Lee, Soo-Hwan;Baik, Eun-Joo;Moon, Chang-Hyun;Jung, Yi-Sook
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.297.3-298
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    • 2002
  • A benzopyranyl derivative. KR32000. synthesized as a plausible KATP opener. has been shown to exert cardioprotective effect in vivo myocardial infarct model. In this study. we investigated whether KR32000 can produce cardioprotective effect against hypoxia- and reactive oxygen species(ROS)-induced injury in heart-derived H9c2 cells. Hypoxic injury was induced by incubating cells in anaerobic chamber (glucose-free. serum-free DMEM. 85% N2. 5% CO2. 10% H2) and oxidative stress was induced by buthionine sulfoximine(BSO). (omitted)

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Nano Particle Charging Characteristics of Aerosol Charge Neutralizers (에어로졸 중화기의 나노 입자 하전 특성)

  • Ji, Jun-Ho;Bae, Swi-Nam;Hwang, Jung-Ho
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.10
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    • pp.1489-1497
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    • 2003
  • Aerosol charge neutralizers with various radioactive sources have been used to apply an equilibrium charge distribution to aerosols of unknown charge distribution. However, the performance of aerosol charge neutralizers is not well known, especially for highly charged particles. Measurements of highly charged particles are needed in air cleaning devices, e.g. electrostatic precipitator, bag filter with a pre-charger, and electrical cyclone. In this study, the particle charging characteristics of two different aerosol charge neutralizers were experimentally investigated for singly charged monodisperse particles and highly charged polydisperse particles. One has radioactive source of $^{85}$ Kr (beta source, 2 mCi) and the other has $^{210}$ Po (alpha source, 0,5 mCi). The air flow rate passing through each aerosol charge neutralizer was changed from 0.2 to 2.5 L/min. The results show that the charge distribution of singly charged monodisperse particles passing through the $^{85}$ Kr aerosol charge neutralizer is well agreed with the Boltzmann equilibrium charge distribution at an air flow rate of 0.3 L/min, However, it deviates from the equilibrium charge distribution when the air flow rates are 0.6, 1,0, and 1,5 L/min, On the other hands, the effect of air flow rate is insignificant for the $^{210}$ Po aerosol charge neutralizer. The non-equilibrium character in charge distribution of highly charged polydisperse particles passing through the $^{85}$ Kr aerosol charge neutralizer greatly depends on the air flow rate, however it is insensitive to the air flow rate for the $^{210}$ Po aerosol charge neutralizer.

Decolorization of Landfill Leachate by White-Rot Fungi (백색부후균에 의한 매립지 침출수의 색도 제거)

  • 김현영;송홍규
    • Korean Journal of Microbiology
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    • v.33 no.1
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    • pp.43-48
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    • 1997
  • 여러가지 난분해성 물질에 대한 생분해능을 지닌 백색부후균에 의한 매립지 침출수의 탈색을 조사하였다. 국내에서 분리한 Coriolus versicolor KR-11W와 Irpex lacteus KR-39W가 이제까지 주로 연구되어 온 Phanerochaete chrysosporium보다 높은 탈색능을 나타내었는데 I. lacteus KR-39W는 산소공급시 10%의 침출수가 함유된 YMG 배지의 진탕배양에서 85%의 색도제거율을 나타내었으며 최소배지에서도 80%의 탈색율을 보였다. P. chrysosporium에 의한 리그닌 분해능 및 분해효소 생성 보고들과 달리 진탕배양이 정치배양보다 탈색능이 높았으며 산소공급은 색도제거에 증가효과가 있었다. 균체 접종량(10-30%)과 온도(25,37.deg. C)는 탈색에 큰 차이를 보이지 않았으나 탄소원과 질소원의 농도는 상당한 영향을 나타내었다. 리그닌 분해효소군의 여러 가지 inducer와 cofactor를 C. versicolor KR-11W 배양에 첨가한 결과 많은 경우 균접종 대조군보다 2배 이상의 탈색율과 lignin peroxidase 활성의 증가를 보였으며 FeS $O_{5}$ 첨가시에는 최대 2.9배의 증가를 나타내었다. 탈색에 관여하는 효소군은 접종물에 이미 어느 정도 존재할 수 있으며 배지 및 배양조건에 따라 그 생성이 변화할 수 있으므로 이런 조건들을 잘 맞출 경우 보다 높은 탈색능이 기대된다.

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Effects of Subchronic Treatment with $AT_{1}$ Receptor Antagonists on Endothelium-dependent and -independent Relaxatio

  • Lee, Byung-Ho
    • Archives of Pharmacal Research
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    • v.19 no.5
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    • pp.390-395
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    • 1996
  • To investigate whether $AT_{1}$ receptor antagonists are acting by increasing endothelium-de-pendent and -independent relaxation of aortas in normotensive rats, $AT_{1}$ receptor antagonists, losartan and KR-30988, and angiotensin converting enzyme inhibitor, captopril, were orally administered for two weeks (50 mg/kg, b.i.d.). THe blood pressure, heart rate and body weight were not significantly changed by losartan, KR-30988 and captopril compared to the control group. In aortic preparations, the $pD_{2}$ of KR-30988 for ACh-induced relaxation was 8.33 $\pm$ 0.16, significantly (p <0.05) lower than that of control group $(7.71 \pm 0.15)$. ACh-induced relaxation was significantly increased on losartan-treated group (p<0.01) at $10^{-6}$ M of ACh, and in captopril-treated group (p<0.05) at the range of $10^{-7}$ -$10^{-5}$ M of ACh. The $pD_{2}$ values for histamine-induced relaxatio of losartan, KR-30988 and captopril were 5.57 $\pm$ 0.10, 5.85 $\pm$ 0.21 and 5.60 $\pm$ 0.01, respectively, with significant differences in all groups (p<0.01) compared to that of control group (5.13 $\pm$ 0.09). ACh-induced relaxations of aortic preparations were not changed by pretreatment of indomethacin ($10_{-5}$ M), and completely bolcked by pretreatment of L-NAME $(10_{-5}M)$ in all groups. Sodium nitroprusside-induced relaxations were not significantly changed by all drugs tested in this experiments. These results suggest that $AT_{1}$ receptor antagonists, losartan and KR-30988, enhance the endothelium-dependent relaxatio on aortic preparations through the release of, or increase sensitivity, to nitric oxide in nor-motensive rats.

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