• Journal of Biomedical Engineering Research
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• v.23 no.5
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• pp.341-349
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• 2002

The target controlled infusion(TCI) pump system is a logical approach to the development of improved administration techniques of an intravenous anaesthetic agent. The principle of TCI system is based on an understanding of the pharmacokinetic properties, three or four compartment model. The TCI system is optimal and flexible control of the plasma drug concentration. But the clinical goal is always to achieve a therapeutic drug effect, not a therapeutic concentration. So we developed the algorithm to target the concentration at the site of drug effect rather than the concentration in the plasma. If impulse drug is inputted into body, the decline of plasma concentration with time is shown, resulting in the expression of the differential equation. Therefore, we must reformulate our three-compartment model as four-compartment model with the effect compartment. And we tested plasma targeting and effect targeting algorithm by computer simulation using four-compartment model. So we developed the TCI capable of applying all intravenous drugs by adjusting individual pharmacokinetic parameters independently.

• Journal of Biosystems Engineering
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• v.23 no.2
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• pp.105-114
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• 1998

Granule application with a boom has merits of accurate application and high field efficiency. In order to develop a boom granule applicator, aerodynamic properties of agrichemicals should be investigated. This study was accomplished to investigate aerodynamic properties of granules and factors affecting on them. The tested agrichemicals were urea, compound fertilizer (17-21-17), sand and zeolite. Basic physical properties of granules such as true density, sphericity, and arithmetic mean diameter for those materials were analyzed. Regression equations for pickup velocity (v$_{p}$) and saltation velocity (v$_{s}$) were proposed by the data transformation and the multi-regression analysis as follows : (equation omitted) where, 0< s < 1, 0< λ$_{i}$< 3, 35 < D/d$_{p}$ < 350, 1000 $_{p}$/p$_{a}$ < 2500 The range of pickup velocity of fertilizers and other agrichemicals were shown to be 10-16m/s and 9-13m/s, respectively. The saltation velocity of fertilizer and other agrichemicals were 3 m/s and 4 m/s, respectively.y.ively.y.y.

• Journal of Ginseng Research
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• v.23 no.3 s.55
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• pp.172-175
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• 1999

The effect of Korean red ginseng extract on the pharmacokinetics of ethanol was examined in 14 male rats and 10 healthy male volunteers. Aqueous red ginseng extract (200 mg/kg), or an equivalent volume of water was administered orally to the rats and followed immediately by treatment with $50\%$ (v/v) ethanol orally (3.2 g/kg). The area under the curve (AVC) and elimination rate constant (Ke) of ethanol were $29.2{\pm}6.2\;g{\cdot}min{\cdot}dl^{-},\;0.51{\pm}0.06\;mg{\cdot}dl^{-}{\cdot}min.^{-}$ in ginseng-treated group and $28.0{\pm}5.6\;g{\cdot}min.{\cdot}dl^{-},0.5{\pm}0.1\;mg{\cdot}dl^{-}{\cdot}min.^{-}$ in control group. These differences were not significant. The volunteers were given orally with 3g of aqueous ginseng, or an equivalent volume of water, followed immediately by Korean alcoholic beverage, Soju (2.4 ml/kg). The AUC and Ke of ethanol for volunteers were $10.6{\pm}2.0\;g{\cdot}min.{\cdot}dl^{-}$ and $0.21{\pm}0.05\;mg{\cdot}dl^{-}{\cdot}min.^{-}$ in ginseng-treated group and $11.0{\pm}2.2\;g{\cdot}min.{\cdot}dl^{-}$ and $0.22{\pm}0.04\;mg{\cdot}dl^{-}{\cdot}min.^{-}$ in control group. These differences were not also significant. These results suggest that an application of red ginseng extract does not have any clinically significant effect on the pharmacokinetics of ethanol.

• Vending industry
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• v.7 no.2 s.20
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• pp.28-33
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• 2007

놀라운 중국의 경제 발전 속도는 세계를 놀라게 하고 있다. 해마다 10% 이상의 고속성장에 경기가 너무 가열되어 문제일 만큼 약동적인 경제성장을 하고 있다. 게다가 그간의 로우 테크(low-tech)위주의 성장에서 탈피, 첨단 기술 산업분야로도 큰 발전을 보이고 있는 상황이다. 이대로 가다가는 중국 경제가 언젠가는 세계 최고가 될 것이라는 전망들도 팽배한 지경이다. 중국의 이러한 경제 성장 분위기라면 자판기 산업 역시도 빠르게 성장해야 마땅한 분위기이다. 하지만 유독 중국의 자판기 산업은 맥을 못 추고 있다 할 만큼 성장세가 더디다. 서서히 산업기반이 발전해 가고 있다고는 하지만 타 산업 분야의 성장에 비하면 크게 미흡하다. 흔히들 2008년 올림픽, 2010엑스포를 기점으로 큰 성장을 할 것이라는 장미 및 청사진 가득한 전망을 내놓지만 현재 분위기로서는 힘겨워 보인다. 내수 성장세가 꾸준히 이어지고 않고 단순히 시간이 간다고 해서 비약적인 성장을 한다고 기대하는 것은 무리이다. 이러한 상황을 볼 때 중국의 자판기 산업은 여전히 가능성의 시장에 머물고 있다 할 수 있다. 실체는 별로 없고 장미 및 청사진만 가득한 게 엄연한 중국의 자판기 산업의 현실이다. 지난 5월31일부터 6월2일까지 개최된 제2회 중국 국제 자동판매기&키오스크 쇼는 이러한 중국자판기 산업의 현실을 여실히 느끼게 해 주었다. 어려운 시장 상황 가운데서도 내일의 가능성에 도전하는 관련 참가업체들의 분투 속에서 그나마 희망을 봤다고 할 수 있을까.

• Korean Journal of Clinical Pharmacy
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• v.8 no.2
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• pp.95-100
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• 1998

Piroxicam-$\beta$-cyclodextrin은 piroxicam을 $\beta$-cyclodextrin으로 포접시킨 비스테로이드성 항염증약물이다. 이러한 포접형 약물은 위장관에서의 흡수속도가 증가하는 것으로 외국자료에서 보고되고 있으며 이는 이 약물의 위장관 내성에 보다 나은 영향을 끼칠 수 있음을 시사하고 있다. 본 연구는 정상성인 한국인을 대상으로 randomized, crossover design에 의해 piroxicam-$\beta-cyclodextrin(Brexin^{(R)})$과 piroxicam 확산정$(Feldene^{(R)})$ 흡수속도를 비교하고자 하였다. 건강한 성인 8명의 피험자를 2군으로 나누어 시험약 또는 대조약을 각각 20 mg씩 20일의 휴약 기간을 두고 이중 맹검으로 교차 투여하였다. 시험약 또는 대조약의 투여 후 24시간 동안 일정 간격으로 채혈하여 HPLC 방법으로 혈장 내 piroxicam 농도를 측정하였다. $AUC_{0-24}\;({\mu}g/mL)$는 piroxicam-$\beta$-cyclodextrin군에서 $56.1\pm4.9$, piroxicam군에서 $57.3\pm5.6$으로 통계적인 유의성이 없었으나, 투여 후 0.5시간에서의 혈중농도는 piroxicam-$\beta$-cyclodextrin군 $2.9\pm0.4\;{\mu}g/mL$, piroxicam군 $1.6\pm0.3\;{\mu}g/mL$으로 통계적인 유의성을 보였다(p<0.05). 또한 최고혈중농도는 piroxicam-$\beta$-cyclodextrin$(4.3\pm0.5\;{\mu} g/mL)\;piroxicam(3.5\pm0.3\l{\mu}g/mL)$,으로 유의성이 있었으며(p<0.05), 흡수 속도상수는 piroxicam-$\beta$-cyclodextrin$(3.00\pm0.49\;h^{-1}), \;piroxicam(1.80\pm0.21\;h^{-1})$이었다(p<0.1). 이상의 결과에서, piroxicam-$\beta$-cyclodextrin정은 piroxicam 확산정과 비교하여 흡수되는 정도는 서로 비슷하지만 흡수 초기의 혈장농도 및 흡수속도상수에서 보다 빠른 약동학적 특성을 나타내었다.

• Journal of fish pathology
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• v.5 no.2
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• pp.135-142
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• 1992

The absorption and excretion times of oxolinic acid(OX) used in farms as new aquatic antibiotics commonly were evaluated with determination of the effects of water temperature and feeding to parameters by using the bioassay technique. On the same time, antibacterial activity and the complex formation of oxolinic acid with serum proteins of two different fishes were compared to those oxytetracycline(OTC). With more than 10 times lower MIC values than those of OTC in the strains among 13 analyzed fish pathogens. OX did not show the decresed antibacterial activity by the binding of serum proteins in carp and tilapia. It implies more powerful potential of OX as aquatic medicine OTC. The serum concentration of OX after different administrations the oral, i.m., i.v and dipping methods were compared. The higher beginning concentration in serum and faster excretion times were obserbed in i.m. and dipping methods respectively. In the oral and i.m. administration, peak serum concentration after 24－48 hrs and slow excretion times demonstrated in both methods. These pharmacokinetic characteristics similar at $30^{\circ}C$ and $20^{\circ}C$ water temperature conditions, however, beginning serum concentration of OX in fish dipped in $50mg/\ell$ sol after starvation for 2 wks was appeared lower than those of fed fish. It suggests the importance of biological condition of the gill or skin for absorption of antibiotics after dipping administration.

• The Korean Journal of Pharmacology
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• v.23 no.1
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• pp.1-7
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• 1987

The renal handling and tissue distribution of pyrazinamide were studied after administration of single dose intravenous injection for 15 min or constant infusion in New Zealand White rabbits. Peak pyrazinamide serum concentration ranged from 57.3 to $105.0{\mu}g/ml$ ($mean{\pm}SD;83.0{\pm}17.8$). The mean half-life of the a phase was $0.143{\pm}0.047$ hr while the ${\beta}$ phase ranged from 1.66 to 3.25 hr($mean{\pm}SD;2.38{\pm}0.57$). The mean steady-state volume of distribution in non-compartmental model was $0.935{\pm}0.362\;L/kg$ Excretion ratio of pyrazinamide was dramatically reduced from 1.02 to 0.30 when unbound serum pyrazinamide concentration was increased from 6.04 to $60.9\;{\mu}g/ml$. The urine flow dependency of renal clearance of pyrazinamide was demonstrated in steady-state serum concentration. The tissue/serum concentration ratio of pyrazinamide was highest in kidney and lowest in skeletal muscle among the tissues examined. The results suggested that a large fraction of pyrazinamide filtered by glomerulus and secreted by renal tubule was reabsorbed and this tubular reabsorption of pyrazinamide might be greatly influenced by urine flow.

• Journal of Biomedical Engineering Research
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• v.20 no.2
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• pp.173-182
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• 1999

Contrast-enhanced CT has an important role in assessing liver lesions, the optimal protocol to get most effective result is not clear. The mein goal when deciding injention protocol is to optimize lesion detectability with rapid scanning when lesion to liver contrast is maximum. For this purpose, we developed a physiological model of the contrast medium enhancement based on the compartment modeling and pharmacokinetics. Blood supply to liver is achieved in two paths. This dual supply characteristic distinguishes the CT enhancement of liver from that of the other organs. The first path is by hepatic artery and to second, by portal vein. However, it is assumed that only gepatic artery can supply blood to hepatocellular carcinoma(HCC) compartment, thus, the difference of contrast enhancement is resulted between normal liver tissue and hepatic tumor. By solving differential equations for each compartment simultaneously using the computer program Matlab, CT contrast-enhancement curves were simulated. The simulated enhancement curves for aortic, hepatic, portal vein, and HCC compartments were compared with the mean enhancement curves from 24 patients exposed to the same protocols as the simulation. These enhancement curves showed a good agreement. Furthermore, we simulated lesion-to-liver curves for various injection protocols, and the effects were analyzed. The variables to be considered in the injection protocol were injection rate, dose, and concentration of contrast material. These data may help to optimize scanning protocols for better diagnosis.

• The korean journal of orthodontics
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• v.35 no.1 s.108
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• pp.60-68
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• 2005

The evaluation of malocclusion has to be done quantitatively and qualitatively. This will be lead toward an analysis of malocclusion severity as well as treatment difficulty. The method of proper evaluation of malocclusion severity and treatment difficulty is necessary to assess treatment effect and efficiency for the orthodontists and to establish fundamentals for planning and executing the health-related policies in private and public institutions. The purposes of this study as the first part of the objective and quantitative analysis of malocclusion were 1) to measure treatment difficulty based on the opinions of several orthodontists. and 2) to investigate the relationships between objective malocclusion severity and subjective treatment difficulty 100 pairs of dental casts that had various types and severity of malocclusion were selected from the orthodontic departments of Kyurghee University and Samsung Medical Center The objective malocclusion severity was measured with the PAR (Peer Assessment Rating) index and the subjective treatment difficulty was evaluated by 8 experienced orthodontists. The relationships between objective malocclusion severity and subjective treatment difficulty were statistically evaluated. There were significant relationships between objective malocclusion severity and subjective treatment difficulty especially in the measurements of the upper anterior alignment, the buccal occlusion. the overjet, the overbite and the midline discrepancy en the malocclusion components. The results of this study can provide the background knowledge to develop a new occlusal index. which contains both the malocclusion severity and treatment difficulty for Korean orthodontists.

• Korean Journal of Veterinary Research
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• v.32 no.1
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• pp.35-39
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• 1992

SMZ is one of the most widely used antibacterial agents in veterinary medicine. It is also used as a growth promotant in many species of domestic animals There are marked species differences in its metabolism and pharmacokinetics. However, its pharmacokinetic and metabolism in rabbits. which are ragarded not only as good laboratorty animals hut also as good economical animals in its own, are lacking. Sex-differences in drug metabolism are well recognized in wide range of animal species including rats. Males are known to he more active than females. It is also know that there are Significant differences in the direction of metabolic pathways. But recently, female goats are reported to be more active in the metabolie capacity of SMZ than the other sex by Dutch researchers at Utrecht. Therefore, it is not easy to make general conclusicn of having higher SMZ metal-die capacity in the male compared to the opposite sex in every animal species. In this regard, the study on metabolic pattern of SMZ in rabbits, which are regarded as hervivorous, is of interest because the dietary habbits of rabbit are comparable to thai of goal, NEW Zealand White rabbits of each sex were given SMZ(35mg/kg) as a bolus injection into the marginalean, vein in order to study its pharmacokinetic profiles(using plasma) anc metabolic pattem(24h urine) as specified in the methods anc materials. 1. In the rabbit, the major metabolic pathway of SMZ was the acetylation(the formation of $N_4AcSMZ$). There were hydroxylation pathways(50HSMZ, $6CH_2OHSMZ$) as well, in the metabolism of SMZ in the rabbit, but minor pathways. 2. No sex differences in the metabolic direction of SMZ and its metabolites formation were found from the urinary excreted metabolites of SMZ out of 24h collected urine. 3. The concentration-time curves of SMZ(35mg/kg, iv) in the plasma compartment were fitted to a one-compartment open model when using a computer program(NONLIN). There was also no difference in the pharmacokinetic pattem of SMZ between two sexes. 4. The emergence of $N_4AcSMZ$ metabolized from SMZ was very fast in the plasma of the rabbit The elimination of $N_4AcSMZ$ was prolonged as compared to that of the parent drug Vie found no sex difference in the elimination pattern of $N_4AcSMZ$ in the rabbit.