• 약학회지
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• 제25권3호
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• pp.101-108
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• 1981

Quantitative determination of capsaicin in biological fluid was investigated. The pharmacokinetic study of capsaicin in rabbits was performed by high-pressure liquid chromatography, equipped with a microparticulate reversed-phase column and a fixed wavelength detector. Elution was carried out using methanolwater(70:30). It allows the quantitative determination at 8-400 ng level. When single dose of capsaicin(4mg/kg) was given to rabbits intravenously, the elimination phase was extremely short with average half-life to 17.35 minute. Urine excretion of capsaicin itself during first 2 hours after intravenous administration (4mg/kg) was 0.004-0.04% of the administered amount. The maximum plasma concentration of capsaicin after oral administration (300mg/kg) was $4{\times}10^{-7}$g/ml at 40 minutes. The $LD_{50}$ of capsaicin in mouse was 0.40mg/kg (i.v.) and 47.2 mg/kg (p.o.) which was determined by Litchfield and Wilcoxon's method, suggesting that the gastrointestinal absorption of capsaicin is poor.

• Environmental Engineering Research
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• 제24권1호
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• pp.31-37
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• 2019

In this paper the results of the biosorption of lead(II) and cadmium(II) with sugarcane bagasse in fixed bed columns are presented. Experimental data were fitted to several models describing the rupture curve for single-component and two-component systems. The percentages of removal of lead and cadmium in single-component systems are 91% and 90%, respectively. In lead-cadmium bicomponent systems the percentage of elimination of lead was 90% and cadmium 92%. In single-component systems, Yoon-Nelson and Thomas models successfully reproduce the rupture curves. In two-component system, the Dose-Response model was the best one reproducing the experimental rupture curves in the entire measured range.

• 한국환경과학회지
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• 제10권4호
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• pp.287-292
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• 2001

A packed bed of volcanic rock was used as deodorizing material to remove hydrogen sulfide($H_2$S) from air in a laboratory-scale column, and was inoculated with Thiobacillus sp. as $H_2S$ oxidizer. The effects of volcanic rock particle size distribution on system pressure drop were examined. Various tests have been conducted to evaluate the effect of $H_2S$ inlet concentration and CBCT(Empty Bed Contact Time) on $H_2S$ elimination. The pressure drop for particles of size range from 5.6 to 10 mm was 14 mm$H_2S$/m at a representative gas velocity of 0.25m/s. Biofilter using scoria and Thiobacillus sp. could get the stable removal efficiencies more than 99.9% under $H_2S$ inlet concentrations in the range from 30 to 1,100ppm at a constant gas flow rate of $15.2{\ell}$/min. $H_2S$ removal efficiencies greater than 99% were observed as long as EBCT was longer than 8sec at the 250ppm of $H_2S$ inlet concentration. When EBCT was reduced to 5.5 sec, $H_2S$ removal efficiency decreased by about 12 percent. The maximum $H_2S$ elimination capacity was determined to be 269g-$H_2S/m^3{\cdot}hr$.

• 한국정보과학회논문지:소프트웨어및응용
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• 제32권10호
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• pp.949-955
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• 2005

본 논문에서는 기존의 전영역 탐색 방식의 계산량을 현저히 줄임과 동시에 동일한 예측 화질을 얻기 위해, 기준 블록의 복잡도 순서와 정방형 서브블럭을 가지고 복잡한 영역 세분화를 통한 고속 블록 매칭(block matching) 알고리즘을 제안하였다. 매칭 에러가 기준 블록 기울기 크기에 비례한다는 것을 이용하여 종래의 순차적인 매칭 스캔(matching scan) 과 행/열 기반의 적응 매칭 스캔 대신, 복잡도에 기초한 정방형 서브 블록(sub-block) 적응 매칭 스캔을 가지고 불필요한 계산을 효율적으로 줄였다. 제안된 알고리즘은 예측 화질의 저하 없이 기존의 PDE(partial distortion elimination) 알고리즘을 이용한 전영역 탐색 방법에 비해 $30\%$의 계산량을 줄였으며, MPEG-2 및 MPEG-4 AVC를 이용하는 비디오 압축 응용분야에 유용하게 사용될 수 있을 것이다.

• Toxicological Research
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• 제20권3호
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• pp.195-203
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• 2004

4-Tert-Octylphenol (OP) is a surfactant additive widely used in the manufacture of a variety of detergents and plastic products. OP can disrupt endocrine function in humans and animals. This study was carried out to obtain toxicokinetic parameters of OP in male Sprague-Dawley (SD) rats. Male rats were administered with OP by single oral application of 200 mg/kg body weight. Blood, urine and tissues samples were taken at several time intervals after administration. Analysis of samples for OP was performed by column-switching high performance liquid chromatography (HPLC). In addition, we exam-ined tissue distribution and accumulation of OP after single oral application of 50, 100, and 200 mg/kg, single intravenous injection of 1, 5 and 10 mg/kg or daily application of 50 mg/kg for 14 consecutive days. After single oral administration of 200 mg/kg, Cmax of 213 $\pm$ 123 ng/ml was reached within the first 1.3 hr (Tmax) in the plasma. AUC was calculated for 1,333$\pm$484 ngㆍhr/ml. The final elimination half-life of plasma was longer than that of urine, but urinary clearance was lower than oral. A very small fraction of OP (Fe < 0.0017%) was excreted in urine within 24 hr. These results indicated that the major excretion route of OP was not urine. The mean maximal tissue distribution of OP was obserbed at 6 hr after treatment and slowly decreased time-dependently. High OP concentrations were detected in fat at 24 hr. The OP in fat was slowly released with longer elimination half-life and lower clearance than that of other tissues. OP was not accumulated in the liver following single oral application but 14-day oral treatments resulted in two-fold accumulation. It was probably due to the saturation of detoxification pathways. On the other hand, the mRNA expression of cytochrome P450 isoforms except CYP2C11 was not affected by OP at any dose. The expression of CYP2C11 mRNA decreased in a dose-dependent manner. This result suggests that OP changes expression of the male-specific cytochrome P450 isoforms in rat liver, and these changes are closely related to the toxic and estrogenic effect of OP.

• The Korean Journal of Ecology
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• 제24권1호
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• pp.35-43
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• 2001

카드뮴과 아연에 각각 그리고 동시에 노출한 총알고둥(Littorina brevicula)에서 중금속의 생체내 축적, 제거 및 세포내 분포 양상을 조사하였다. 총알고둥을 카드뮴 400 $\mu\textrm{g}$/L 또는 아연 3000 $\mu\textrm{g}$/L에 각각 90일간 노출하였을 경우, 각 중금속의 축적량은 노출기간에 따라 증가하였으며, 70일 이후에는 더 이상 축적량이 증가하지 않았다. 카드뮴과 아연을 동시에 노출하였을 경우에는 각각의 중금속에 노출하였을 경우에 비해 아연의 축적량은 증가하였으나, 카드뮴의 축적량은 감소하였다. 노출실험에 이어 수행한 42일간의 청장실험 결과, 카드뮴은 체외로 제거되지 않았으나, 아연은 제거되었다. 특히 카드뮴과 아연에 동시 노출한 총알고둥의 경우에 아연은 더 신속히 제거되었다. 총알고둥을 카드뮴과 아연에 각각 70일 동안 노출한 후, 체내로 흡수된 카드뮴의 약 60%가 soluble fraction에 분포하고 있었으며, 아연의 75%는 insoluble fraction에 분포하고 있었다. 이러한 경향은 카드뮴과 아연의 동시 노출시에도 유사하게 나타났다. 카드뮴과 아연은 soluble part내의 리간드(ligand) 와의 결합 양상에서도 차이를 나타냈는데, 카드뮴은 90% 이상이 약 6.5 kDa크기의 MBP-1(Metal-Binding Protein-1)과 결합하고 있었으나, 아연은 HMW(High molecular weight fraction, >60 kDa), MBP-1, MBP-2, LMW(Low molecular weight fraction <1 kDa)에 고루 분포하는 것으로 나타났다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권1호
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• pp.227-247
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• 2018

For intermittently connected wireless sensor networks deployed in hash environments, sensor nodes may fail due to internal or external reasons at any time. In the process of data collection and recovery, we need to speed up as much as possible so that all the sensory data can be restored by accessing as few survivors as possible. In this paper a novel redundant data storage algorithm based on minimum spanning tree and quasi-randomized matrix-QRNCDS is proposed. QRNCDS disseminates k source data packets to n sensor nodes in the network (n>k) according to the minimum spanning tree traversal mechanism. Every node stores only one encoded data packet in its storage which is the XOR result of the received source data packets in accordance with the quasi-randomized matrix theory. The algorithm adopts the minimum spanning tree traversal rule to reduce the complexity of the traversal message of the source packets. In order to solve the problem that some source packets cannot be restored if the random matrix is not full column rank, the semi-randomized network coding method is used in QRNCDS. Each source node only needs to store its own source data packet, and the storage nodes choose to receive or not. In the decoding phase, Gaussian Elimination and Belief Propagation are combined to improve the probability and efficiency of data decoding. As a result, part of the source data can be recovered in the case of semi-random matrix without full column rank. The simulation results show that QRNCDS has lower energy consumption, higher data collection efficiency, higher decoding efficiency, smaller data storage redundancy and larger network fault tolerance.

• 한국임상약학회지
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• 제18권2호
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• pp.120-123
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• 2008

The purpose of this study was to investigate the effect of naringin, one of flavonoids, on the pharmacokinetics and bioavailability of nimodipine in rabbits. Pharmacokinetic parameters of nimodipine were determined in rabbits after oral administration of nimodipine (16 mg/kg) with or without naringin (1, 5 or 15 mg/kg). Nimodipine was analyzed by high performance liquid chromatography using Hypersil ODS column. Naringin significantly (p<0.05) increased the area under the plasma concentration-time curve (AUC) and the peak concentration ($C_{max}$) of nimodipine at 5 and 15 mg/kg. The absolute bioavailability (AB%) of nimodipine by prescence of naringin (5 or 15 mg/kg) increased from 32.2-36.9% (p<0.05) compared to the control (22.0%). However, presence of naringin had no significant effect on the elimination rate constant ($K_{el}$) of nimodipine. There were no apparent changes of the time of peak concentration ($T_{max}$) of nimodipine by coadministration. These results suggest that the increased bioavailability and the significant changes of these pharmacokinetic parameters of nimodipine by naringin may be attributed to the potential of narigin to inhibit cytochrome P450 (CYP) 3A4 and P-glycoprotein efflux pump in the liver and intestinal mucosa.

• Biomolecules & Therapeutics
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• 제13권2호
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• pp.90-94
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• 2005

Prazosin hydrochloride is an antihypertensive drug with selective ${\alpha}_1$-adrenoreceptor blocking effects. A simple high performance liquid chromatographic method has been developed and validated for the quantitative determination of prazosin in human plasma. A reversed-phase C18 column was used for the separation of prazosin and terazosin (internal standard) with a mobile phase composed of water, acetonitrile and triethylamine(75:25:0.1, V/V;pH5.0) at a flow rate of 1.5 ml/min. the fluorescence detector was set at excitation and emissionwavelengths of 250 and 370 nm, respectively. Intra-and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification of 0.5 ng/ml. Good recovery (>80%) was seen in plasma. Prazosin was stable in human plasma under various storage conditions. This method was used successfully for a pharmacokinetic study in plasma after oral administration of a single 2-mg dose as prazosin base to 16 healthy volunteers. The maximum plasma concentration of prazosin was 23.1 ${\pm}$ 16.5 ng/ml at 2.1 h, and the mean area under the curve and elimination half-life were calculated to be 108.4 ${\pm}$ 74.2 ng ${\cdot}$hr/ml and 2.5 ${\pm}$ 0.6 h, respectively.

• Biomolecules & Therapeutics
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• 제14권1호
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• pp.40-44
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• 2006

Mirtazapine is an antidepressant agent with dual action on both the noradrenergic and serotonergic neurotransmitter systems. A simple high performance liquid chromatographic method has been developed and validated for the quantitative determination of mirtazapine in human plasma. A reversed-phase Cl8 column was used for the determination of mirtazapine with a mobile phase composed of 0.01M ammonium acetate solution (pH 4.2) and acetonitrile (75:25, v/v%) at a flow rate of 1.2 mL/min. Terazosin hydrochloride was used as an internal standard. The fluorescence detector was set at excitation and emission wavelengths of 290 and 350 nm, respectively. Intra- and inter-day precision and accuracy were acceptable for all quality control samples including the lower limit of quantification of 3 ng/mL. Mirtazapine was stable in human plasma under various storage conditions. This method was used successfully for a pharmacokinetic study using plasma samples after oral administration of a single 30 mg dose as mirtazapine base to 8 healthy volunteers. The maximum plasma concentration of mirtazapine was $64.1{\pm}28.0ng/mL$ at 1.8 h, and the area under the curve and elimination half-life were calculated to be $674.1{\pm}218.5ng\;h/mL\;and\;23.4{\pm}3.8h$, respectively.