• 제목/요약/키워드: Half Life

검색결과 1,829건 처리시간 0.024초

반코마이신의 시간 약물동태학 (Chronopharmacokinetics of Vancomycin in Normal Volunteers)

  • 최준식;유재신;최병철;김진;범진필;최경업
    • 한국임상약학회지
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    • 제6권2호
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    • pp.1-6
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    • 1996
  • Carcadian rhythm dependence of vancomycin pharmacokinetics was evaluated in 5 normal volunteers receiving a single intravenous 1.0 g dose of vancomycin at 8 o'clock in the morning and another occasion at 8 o'clock in the evening in a crossover manner. The serum data were subjected to simultaneous computer nonlinear least squares regression analysis using a two-compartment pbarmacokinetic model. The mean half-life of vancomycin was $4.78\pm0.81$ hr in the morning and $4.25\pm0.51$ hr in the evening. The mean total body clearance of vancomycin was $1.29\pm0.58$ hr in the morning and $5.58\pm0.48$ hr in the evening. No circadian rhythm was found to be apparent in normal volunteers. The mean in intrasubject difference in the half-life between 8 A.M. and 8 P.M. was $15.4\%$ with fluctuations ranging from $10.4\sim33.8\%$, It is reasonable to consider individual circadian rhythm for effective dosage regimen of vancomycin in clinical chronotherapeutics.

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정전기 재해예방을 위한 제전복의 제전특성에 관한 연구 (A Study on the Antistatic characteristics of Antistatic Garments for the Prevention of Static Electricity Hazards)

  • 정재희
    • 한국안전학회지
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    • 제5권1호
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    • pp.57-66
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    • 1990
  • The purpose of this study is to investigate electrostatic charge condition and possibility of electrostatic hazards in case of putting on synthetic smocks and antistatic garments for the purpose of prevention of electrostatic hazards due to a human body electrical charge. It is shown in case of a synthetic smocks, electrostatic voltage by friction is about 2,900 (V), half life period is 12 second, and electrostatic charge is 1.4―1.8 ($\mu$ C). When putting on a synthetic smocks, electrostatic voltage is 2,500―2,800(V). When putting on a jumper of chemical fiber, electrostatic voltage is 8,000(V) . It is, therfore, possible to cause a electrostatic hazards. It is also shown in case of a antistatic garments, electrostatic voltage by friction is 87(V) ―280(V) (washing 90 times), half life period is 3―5 second, and electrostatic charge is 0.24―0.28($\mu$ C) which is much lower than 0.6($\mu$ C) limitation of fire and explosion occurance. When putting on a antistatic garments, electrostatic voltage is 10(V) ―125(V). In conclusion, it is shown when putting on a antistatic garments it is possible to prevent a electrostatic hazards such as fire or explosion due to human body, to prevent a destruction of semiconductor elements and capacity decline, and to prevent a misoperation of automation facilities and semiconductor electric and electronic products.

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Novel AGLP-1 albumin fusion protein as a long-lasting agent for type 2 diabetes

  • Kim, Yong-Mo;Lee, Sang Mee;Chung, Hye-Shin
    • BMB Reports
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    • 제46권12호
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    • pp.606-610
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    • 2013
  • Glucagon like peptide-1 (GLP-1) regulates glucose mediated-insulin secretion, nutrient accumulation, and ${\beta}$-cell growth. Despite the potential therapeutic usage for type 2 diabetes (T2D), GLP-1 has a short half-life in vivo ($t_{1/2}$ <2 min). In an attempt to prolong half-life, GLP-1 fusion proteins were genetically engineered: GLP-1 human serum albumin fusion (GLP-1/HSA), AGLP-1/HSA which has an additional alanine at the N-terminus of GLP-1, and AGLP-1-L/HSA, in which a peptide linker is inserted between AGLP-1 and HSA. Recombinant fusion proteins secreted from the Chinese Hamster Ovary-K1 (CHO-K1) cell line were purified with high purity (>96%). AGLP-1 fusion protein was resistant against the dipeptidyl peptidase-IV (DPP-IV). The fusion proteins activated cAMP-mediated signaling in rat insulinoma INS-1 cells. Furthermore, a C57BL/6N mice pharmacodynamics study exhibited that AGLP-1-L/HSA effectively reduced blood glucose level compared to AGLP-1/HSA.

사회과학문헌 인용분석연구 -경제학.문헌정보학.행정학 중심- (A Study on Citation Analysis of Social Science Literature)

  • 정진식
    • 정보관리학회지
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    • 제11권2호
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    • pp.31-48
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    • 1994
  • 본 연구는 우리나라 경제학, 문헌정보학, 행정학 분야의 3개 학회지 논문에 인용된 문헌을 자료의 형태별, 발행지별로 발행년도를 기준으로 분석하여 문헌의 인용 분포와 이용가치 감소 현상 즉 반감기를 측정하였다. 연구 결과 반감기는 단행본 6.76년, 학술잡지기사 8.07년, 보고서 6.49년, 논문 3.45년으로 나타났으며, 국내 문헌 32.21%에 비해 외국문헌은 67.79%로 3개 분야의 연구자들이 외국 문헌에 상당한 비중을 두고 있는 것으로 분석되었다.

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110mAg 간섭으로부터 137Cs 정량평가를 위한 드럼핵종분석 교정기술 (Calibration Method of the Tomographic Gamma Scan Techniques Available for Accurately Characterizing 137Cs from 110mAg Interference)

  • 정성엽
    • 방사성폐기물학회지
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    • 제14권1호
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    • pp.57-61
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    • 2016
  • The Tomographic Gamma Scan (TGS) technique partitions radioactive waste drums into $10{\times}10{\times}16$ voxels and assays both the density and concentration of radioactivity for each voxel thus providing for improved accuracy, when compared to the traditional Non-Destructive Assay(NDA) techniques. It could decrease the degree of precision measurement since there is a trade-off between spatial resolution and precision. This latter drawback is compensated by expanding the Region of Interest (ROI) that differentiates the full energy peaks, which, in turn, results in an optimized degree of precision. The enlarged ROI, however, increases the probability of interference among those nuclides that emit energies in the adjacent spectrum. This study has identified the cause of such interference for the reference nuclide of the TGS technique, $^{137}Cs$ (661.66 keV, half-life 30.5 years), to be $^{110m}Ag$ (657.75 keV, half-life 249.76 days). A new calibration method of determining the optimized ROI was developed, and its effectiveness in accurately characterizing $^{137}Cs$ and eliminating the interference was further ascertained.

돼지에서 근육주사한 Abamectin에 대한 HPTLC 분석 및 약물동태학 (Quantitation of abamectin by HPTLC and its pharmacokinetics after intramuscular injection in pigs)

  • 박승춘;윤효인
    • 대한수의학회지
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    • 제40권1호
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    • pp.35-41
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    • 2000
  • We established a new method to analyze abamectin using HPTLC (high performance thin layer chromatography) in order to obtain its pharmacokinetic profiles in pigs. Recovery of abamectin in pig serum after fluorescence derivatization was $80.01{\pm}3.82%$ at 0.1ppm and $83.67{\pm}3.63%$ at 10ppm, respectively. Detection reproducibility in terms of coefficient variation (c.v.) was 3.09% and 2.74% (intra-day), and 3.71% and 51.7%(inter-day), for 0.1 and 10ppm, respectively. Pharmacokinetics of abamectin was studied in five Yorkshire-Landrace mixed bred male pigs ($35.0{\pm}2.7kg$) administered intramuscularly 0.3mg/kg b.w. Pharmacokinetic profiles of abamectin in pigs were described by the 1-compartment open model with first-order absorption and first-order elimination. AUC (area under the curve) was $262.65{\pm}16.44ng{\cdot}day/ml$ and the biological elimination half-life ($t_{1/2},\;k_e$) was $5.28{\pm}0.84$ days, indicating somewhat high bioavailability and long half-life by the intramuscular route. We suggest intramucular injection of abamectin could be also used in place of the recommended route of its subcutaneous administration so far.

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염산(鹽酸)Promazine 주사제(注射劑)의 안정화(安定化)에 관한 연구(硏究) (Study on Stabilization of Promazine Hydrochloride Injection)

  • 이완하;지웅길;양재헌
    • Journal of Pharmaceutical Investigation
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    • 제3권3호
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    • pp.5-15
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    • 1973
  • The stabilizing effect of promazine hydrochloride injectin was tested by irradiation of sun lamp(5,000 Lux) on their acid solution sealed in ampules under various stabilizers. The result of experimentation on the color change, the remaining proportion and the half life of promazine hydrochloride solution is as follows. 1. Instability of promazine hydrochloride solution is mainly caused by the sunlight and oxygen. 2. The pH range of promazine hydrochloride injection is recommended to $pH\;4.4{\sim}5.2$ 3. The decomposition of promazine hydrochloride by the sunlight is composed of pseudo zero order reaction when It maintains colorless solution. 4. The half life of 0.5% promazine hydrochloride injection was 30 hrs. under sun lamp irradiation, but it was delayed to 84 hrs. by the simple stabilizer and to 175 hrs. by compound stabilizer. 5. The stabilizing effect of promazine .hydrochloride injection adding sod. metabisulfite$(Na_2S_2O_5)$ was most excellent in various simple stabilizers and adding $Na_2S_2O_5$ to nicotinic acid, $Na_2S_2O_5$ to nicotinamide were more excellent than other compound stabilizers.

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랫드에서의 UTI의 약물동태학 및 조직 분포 (Pharmacokinetics and Tissue Distribution of UTI in the Rat)

  • 정요찬;윤효인;조명행;박병권;발일현;김복환;송동호
    • Biomolecules & Therapeutics
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    • 제4권3호
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    • pp.265-270
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    • 1996
  • The purpose of this study was to determine pharmacokinetic parameters and tissue distribution patters of urinary trypsin inhibitor(UTI) in Sprague-Dawley rats. $Na^{125}$I was conjugated to UTI to make $^{125}I-UTI$ and the concentrations were determined by $\gamma$-counter. With the aid of nonlinear least-square regression analysis for i.v bolus injection of 1,000 unit UTI including $^{125}I-UTI$, the temporal concentration curves were best fitted by 2-compartment open model. The distribution phase half-life was 0.39$\pm$0.02 hours whereas the elimination half-life was 12.99$\pm$1.05 hours in male rats. The volume of distribution and total body clearance in male rats were 0.28$\pm$0.01 1/kg and 83.16$\pm$1.15 ml/kg/h, respectively. We could not find any difference of pharmacokinetic parameters of UTI between male and female rats. UTI were distributed widely in rat organs. In both male and female rats, the kidney was the highest distributed organ. Amount of UTI in 24 hour cumulative urine in male rats was 36.22$\pm$8.74% and that in 48 hours was 43.32$\pm$10.55%. Excretion via feces was very scanty, with the 24 hours cumulative amount being only 2.76$\pm$0.97%. This data suggest the main excretion route of UTI is urine.

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마우스에서 VEGF발현 Naked DNA 벡터인 pCK-VEGF의 약동력학 및 조직내 분포 (Pharmacokinetics and Biodistribution in Mice of pCK-VEGF Expressing Human Vascular Endothelial Growth Factor)

  • 도현미;고준일;이종진;손미원;조홍찬;김종묵;김병문;김선영
    • 약학회지
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    • 제45권1호
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    • pp.71-77
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    • 2001
  • We recently developed a high efficiency expression vectors pCK, which drives a high level of gene expression in the skeletal muscles of mice. In this study, we investigated the pharmacokinetics and biodistribution of pCK-VEGF expressing human VEGF165 after intravenous or intramuscular administration. The quantity of pCK-VEGF in the tissues of mice was measured by the PCR method which has a detection limit of approximately 1 pg of the exogenously added plasmid. In the case of intravenous administration, the half life of the pCK-VEGF plasmid in the bloodstream was 1.68 min. After intra-muscular administration, the half life of pCK-VEGF plasmid in the bloodstream was 6.78 min. At 90 min post-administration, 30% of the injected pCK-VEGF was found at the site of injection, where it persisted for up to 8 hours. Less than 1.6% of the injected pCK-VEGF plasmid DNA was detected in highly vascularized tissues such as the lung, kidney; and liver at 90 min post-administration, but the plasmid was undetectable at later time points. These results suggested that intramuscularly administrated pCK-VEGF persisted for longer periods of time in muscles than in other tissues and that direct intra-muscular injection of pCK-VEGF might be useful for local therapeutic angiogenesis.

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U-937 세포에 있어서 세라마이드에 의한 c-jun 유전자 발현의 조절 (Ceramide-Mediated c-jun Gene Expression in U-937 Cells)

  • 김원호;김미영;최경희
    • 약학회지
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    • 제41권1호
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    • pp.81-85
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    • 1997
  • Ceramide has been suggested as an important mediator of the effects of extracellular agonists on cell growth inhibition, differentiation, apoptosis. However the biochemical sign aling mechanism involved in transducing the effects of ceramide on leukemia cell differentiation is still unclear. In these respects, we examined the regulatory effects of ceramide on c-jun gene expression during differentiation. In U-937 cells. ceramide increased c-jun mRNA levels in a time-dependent manner. The half life, of c-jun mRNA was 30 min. In contrast, inhibition of protein synthesis with cycloheximide in the absence, of transcription with actinomycin D increased the half-life of c-jun mRNA in ceramide-treated U-937 cells to more than 90 min. In order to examine whether ceramide-inhibited c-jun gene expression is regulated through ceramide-activated protein phosphatase (CAPP), a direct target for the action of ceramide, okadaic acid were treated to the cells. Okadaic acid inhibited enhancement of c-jun mRNA induced by C2-ceramide in a dose-dependent manner. These results suggested that ceramide increases c-jun mRNA level during differentiation in U-937 cells and regulates the gene expression on posttranscriptional level. In addition, we provide the evidence that CAPP is involved in ceramide-induced c-jun gene expression in U-937 cells.

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