• Title/Summary/Keyword: Effect compartment model

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Pharmacokinetic-Pharmacodynamic Modeling of a Direct Thrombin Inhibitor, Argatroban, in Rats

  • Park, Eun-Hye;Shin, Beom-Soo;Yun, Chi-Ho;Lee, Mann-Hyung;Yoo, Sun-Dong
    • Journal of Pharmaceutical Investigation
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    • v.39 no.5
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    • pp.373-379
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    • 2009
  • This study was conducted to develop a pharmacokinetic-pharmacodynamic (PK/PD) model of a direct thrombin inhibitor, argatroban to predict the concentration-effect profiles in rats. Argatroban was i.v. injected to rats at 0. 2, 0.8 and 3.2 mg/kg doses (n = 4-5 per dose), and plasma drug levels were determined by a validated LC/MS/MS assay. The pharmacokinetics of argatroban was linear over the i.v. dose range studied. The thrombin time (TT) and the activated partial thromboplastin time (aPTT) were measured in rat plasma and they were found to linearly increase with increasing the dose. A 2-compartment pharmacokinetic model linked with an indirect response pharmacodynamic model was successfully utilized to evaluate the drug concentration-response relationship.

Jet Entrainment Effect in Buoyant Jet and Iso-Thermal Fire Modeling (부력제트의 주위공기 유입효과 및 등온기체 모델링)

  • Lee, Eui-Ju
    • Fire Science and Engineering
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    • v.23 no.6
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    • pp.111-115
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    • 2009
  • Acetone LIF and Rayleigh scattering measurements were performed to identify the entrainment of ambient air in the buoyant jet qualitatively. The air entrainment near nozzle exit was enhanced with increasing both an axial distance and Reynolds number. The results supported that the air entrainment had to be considered in isothermal model for the development of its accuracy. Also, this paper provided an isothermal model based on the ideal plume, of which radiative heat loss fraction was assumed to 0.35 and the entainment of isothermal jet was considered. This simple model could be used in compartment or semi-enclosure fires such as tunnel, and it is more reliable because of introducing entrainment effect in isothermal jet.

Computational Study on the Hemodynamic Behaviors of the Human Cardiovascular System with an Acute Arteriovenous Fistula (급성 동정맥루를 포함하는 인체 심혈관계의 혈류역학적 거동에 관한 수치 해석적 연구)

  • 변수영;손정락;심은보;노승탁
    • Journal of Biomedical Engineering Research
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    • v.24 no.4
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    • pp.329-337
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    • 2003
  • Blood in congenital or acquired AY fistula(arteriovenous fistula) flows from arteries directly to veins. detouring peripheral micro-circulation. This makes a great effect on the hemodynamics of human cardiovascular system. In this study, a computational method using lumped parameter mode) was proposed to simulate the cardiovascular hemodynamics of patients with acute AV fistula The cardiovascular system model with a fistula compartment in left lower limb was built using 17 standard lumped compartments. Using fourth order Runge-Kutta method. we solved numerically the unsteady linear set of the ordinary differential equations resulting from application of Kirchhoff's law to the lumped parameter hemodynamic model. The baroreceptor reflex system was implemented to explain the auto-regulation effect of the cardiovascular system with acute AV fistula.

Estimation of Urea and Vitamin B12 Concentrations in the Body using Two Compartment Model (신 부전증 환자의 요소 및 비타민 B12 의 체내농도 추정)

  • 장호남;박한철
    • Journal of Biomedical Engineering Research
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    • v.3 no.1
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    • pp.9-16
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    • 1982
  • Removal of urea and vitamin B12 was simulated using two pool models with closed loop dialysis, open loop dialysis, and hemodiafiltrations with predilution and postdilulion. It was found that urea removal was limited by dialyzer clearance, however B12 removal was limited both by the resistance between ECF and ICF and by dialyzer clearance. Open loop dialysis was better than closed loop dialysis in terms of dialysate requirement and removal efficiency. Residual renal function plays an important role in removing vitamin B12. Dialysis frequency more than twice/wide does not have great effect on removal efficiency, but has the effect of reducing the difference between maximum and minimum cancentrations during dialysis period.

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Investigation on Stray Magnetic Field of High-Speed Maglev

  • Sun, Yan;Lee, Chang-Young;Jo, Jeong-Min;Lee, Jin-Ho;Han, Young-Jae
    • Journal of international Conference on Electrical Machines and Systems
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    • v.3 no.1
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    • pp.27-31
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    • 2014
  • Magnetic fields (MF) generated both on board the vehicle and along the guideway provide levitation and propulsion forces. High speed maglev trains adopt electromagnet or superconducting magnet to realize levitation and propulsion functions. However, stray fields existing in passenger compartment and regions surrounding the vehicle and guideway have effect on passengers and environment. To investigate stray magnetic field effect, model of Transrapid and MLX are studied.

Population Pharmacokinetics of Midazolam in Healthy Koreans: Effect of Cytochrome P450 3A-mediated Drug-drug Interaction (건강한 한국인에서 미다졸람 집단약동학 분석: CYP3A 매개 약물상호작용 평가)

  • Shin, Kwang-Hee
    • Korean Journal of Clinical Pharmacy
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    • v.26 no.4
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    • pp.312-317
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    • 2016
  • Objective: Midazolam is mainly metabolized by cytochrome P450 (CYP) 3A. Inhibition or induction of CYP3A can affect the pharmacological activity of midazolam. The aims of this study were to develop a population pharmacokinetic (PK) model and evaluate the effect of CYP3A-mediated interactions among ketoconazole, rifampicin, and midazolam. Methods: Three-treatment, three-period, crossover study was conducted in 24 healthy male subjects. Each subject received 1 mg midazolam (control), 1 mg midazolam after pretreatment with 400 mg ketoconazole once daily for 4 days (CYP3A inhibition phase), and 2.5 mg midazolam after pretreatment with 600 mg rifampicin once daily for 10 days (CYP3A induction phase). The population PK analysis was performed using a nonlinear mixed effect model ($NONMEM^{(R)}$ 7.2) based on plasma midazolam concentrations. The PK model was developed, and the first-order conditional estimation with interaction was applied for the model run. A three-compartment model with first-order elimination described the PK. The influence of ketoconazole and rifampicin, CYP3A5 genotype, and demographic characteristics on PK parameters was examined. Goodness-of-fit (GOF) diagnostics and visual predictive checks, as well as bootstrap were used to evaluate the adequacy of the model fit and predictions. Results: Twenty-four subjects contributed to 900 midazolam concentrations. The final parameter estimates (% relative standard error, RSE) were as follows; clearance (CL), 31.8 L/h (6.0%); inter-compartmental clearance (Q) 2, 36.4 L/h (9.7%); Q3, 7.37 L/h (12.0%), volume of distribution (V) 1, 70.7 L (3.6%), V2, 32.9 L (8.8%); and V3, 44.4 L (6.7%). The midazolam CL decreased and increased to 32.5 and 199.9% in the inhibition and induction phases, respectively, compared to that in control phase. Conclusion: A PK model for midazolam co-treatment with ketoconazole and rifampicin was developed using data of healthy volunteers, and the subject's CYP3A status influenced the midazolam PK parameters. Therefore, a population PK model with enzyme-mediated drug interactions may be useful for quantitatively predicting PK alterations.

Effect of temperature on pharmacokinetics of nalidixic acid, piromidic acid and oxolinic acid in olive flounder Paralichthys olivaceus following oral administration (넙치, Paralichthys olivaceus에 nalidixic acid, piromidic acid, oxolinic acid의 경구투여 약물동태에 미치는 수온의 영향)

  • Jung, Sung-Hee;Kim, Jin-Woo;Seo, Jung-Soo;Choi, Dong-Lim;Jee, Bo-Young;Park, Myoung-Ae
    • Journal of fish pathology
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    • v.23 no.1
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    • pp.57-67
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    • 2010
  • Effects of temperature ($13{\pm}1.5^{\circ}C$, $23{\pm}1.5^{\circ}C$) on the pharmacokinetic properties of nalidixic acid (NA), piromidic acid (PA) and oxolinic acid (OA) were studied after oral administration to cultured olive flounder, Paralichthys olivaceus. Serum concentrations of these antimicrobials were determined after oral administration of a single dosage of 60 mg/kg body weight (average 700 g). At $23{\pm}1.5^{\circ}C$, the peak serum concentrations of NA, PA and OA, which attained at 10 h, 24 h and 30 h post-dose, were 11.55, 3.79 and $1.12{\mu}g/m\ell$, respectively. At $13{\pm}1.5^{\circ}C$, the peak serum concentrations of NA, PA and OA, which attained at 10 h, 15 h and 30 h post-dose, were 6.36, 1.4 and $1.01{\mu}g/m\ell$, respectively. Better absorption of NA and PA was noted at $23{\pm}1.5^{\circ}C$ compared to $23{\pm}13^{\circ}C$. The elimination of NA from serum of olive flounder was considerably faster at $23{\pm}1.5^{\circ}C$ than at $13{\pm}1.5^{\circ}C$. However, both absorption and elimination of OA were not affected significantly by temperature. The kinetic profile of absorption, distribution and elimination of these antimicrobials in serum were analyzed by fitting to a one- and two compartment model, with WinNonlin program. In the one compartment model for NA, AUC, Tmax and Cmax at $23{\pm}1.5^{\circ}C$ were $258.26{\mu}g{\cdot}h/m\ell$, 10.67 h and $8.91{\mu}g/m\ell$, respectively. The AUC, $T_{max}$ and $C_{max}$ at $13{\pm}1.5^{\circ}C$ were $341.45 {\mu}g{\cdot}h/m\ell$, 7.72 h and $6.23{\mu}g/m\ell$, respectively. In the one compartment model for PA, AUC, $T_{max}$ and $C_{max}$ at $23{\pm}1.5^{\circ}C$ were $248.12{\mu}g{\cdot}h/m\ell$, 21.15 h and $3.09{\mu}g/m\ell$, respectively. The AUC, $T_{max}$ and $C_{max}$ at $13{\pm}1.5^{\circ}C$ were $103.89{\mu}g{\cdot}h/m\ell$, 12.89 h and $1.22{\mu}g/m\ell$, respectively. In the two compartment model for OA, AUC, $T_{max}$ and $C_{max}$ at $23{\pm}1.5^{\circ}C$ were $138.20{\mu}g{\cdot}h/m\ell$, 23.95 h and $1.06{\mu}g/m\ell$, respectively. The AUC, $T_{max}$ and $T_{max}$ at $13{\pm}1.5^{\circ}C$ were $159.10{\mu}g{\cdot}h/m\ell$, 28.03 h and $1.02{\mu}g/m\ell$, respectively.

Escape response of juvenile seabream with rockfish from the separating model codend in tank experiments

  • KIM, Yonghae
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.52 no.2
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    • pp.88-95
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    • 2016
  • Most grid sorting has been used to sort out flatfish in shrimp fisheries, while double grid systems have been tested to separate smaller shrimp. The escape of juvenile red seabream through separating panels made with steel grids or large mesh tested for masking effects in a two-species system. Fish behavior was observed in a circulating water tank. The escape rate was 20% greater with the separating codends than with the normal codend in the single-species experiments. The rates in the two-species experiments were 30% or 20% greater than the single-species rates for the normal or separating codends, respectively. The seabream retention rates in the grid separator codend decreased as rockfish retention increased, possibly due to a threat effect. Conversely, the retention rate of both species increased concurrently in the net separator, possibly due to a masking effect. The escape rates of juvenile red seabream varied by compartment in the mesh separating codend. These results suggest that grid separating codends can be used in the field as towed fishing gear to reduce juvenile catch.

ANALYSIS ON THE VIBRO-ACOUSTICAL CHARACTERISTICS OF A PANEL-CAVITY COUPLED SYSTEM

  • Kim, Seock-Hyun;Kang, Sang-Wook;Lee, Jang-Moo
    • Journal of Theoretical and Applied Mechanics
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    • v.3 no.1
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    • pp.34-44
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    • 2002
  • Theoretical analysis Is carried out to identify the modal coupling effect between some particular acoustic modes of a vehicle compartment cavity and vibration modes of body panels like side doors, roof or floor. A simplified panel-cavity coupled model is investigated on the coupled resonance frequencies, modes and frequency response characteristics. Through parametric study, It Is possible to explain how the acoustic response of a coupled system will be determined by the vibration and acoustic property of the individual panel and cavity system. Full coupled system shows some interesting features different from those of the semi-coupled system In frequency, mode and acoustic response.

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Steady states and dynamic behavior of an LDPE autoclave reactor

  • Lee, Jin-Suk;Chang, Kil-Sang;Kim, Jae-Yeon;Rhee, Hyun-Ku
    • 제어로봇시스템학회:학술대회논문집
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    • 1989.10a
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    • pp.813-818
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    • 1989
  • A two compartmented autoclave reactor for the polymerization of low density polyethylene is analyzed with respect to the effects of heat transfer and operation variables. Each compartment being considered as a completely mixed cell, two CSTRs model is proposed. The system shows various multiplicity features of steady state and periodic oscillatory motions. Heat removal efficiency and initiator supplement appear to have significant effect on the conversion of monomer with the temperature properly maintained, which should be taken into account in the reactor design.

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