• Archives of Pharmacal Research
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• v.25 no.6
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• pp.969-972
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• 2002

The alteration in the pharmacokinetic behaviors of organic cations (OCs) in rats during acute inflammation (AI) was investigated. AI was induced by an intraperitoneal injection of lipopolysaccharide (LPS, 5 mg/kg) 24 hr prior to the start of pharmacokinetic studies. Tributylmethylammonium (TBuMA) was selected as a model OC since it is largely excreted into bile, and is neither metabolized nor binds to proteins in the body. When TBuMA was administered intravenously to AI rats at a dose of 6.6 $\mu$mole/kg, the AUC was increased, while biliary excretion (i.e., cumulative amount and apparent clearance) was decreased compared to normal rats. When TBuMA was administered intravenously to AI rats at a constant rate (i.e., a bolus injection at a dose of 1.5 $\mu$mole/kg followed by a constant infusion at a rate of 1.5 $\mu$mole/kg/hr for 165 min), steady-state concentrations of plasma and liver concentrations of TBuMA were increased significantly, while in vivo hepatic uptake (amount) and canalicular excretion (clearance) were decreased. These results are consistent with a hypothesis in which both the sinusoidal uptake of TBuMA into hepatocytes via the OCT1 and the canalicular excretion of the compound from hepatocytes via the P-gp are decreased by LPS-induced AI.

• Archives of Pharmacal Research
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• v.4 no.2
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• pp.109-115
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• 1981

In the present investigation, an attempt has been made to apply the methods of classical chemical kinetics to the hydrolytic reaction of pipethanate hydrochloride. By successively keeping all but one variable essentially constant, it has been possible to resolve the overall effect of the individual contributing factors. Since nearly all commercial pipethanate preparations are formulated with antacid, studies were made at several constant hydrogen ion concentration ranging pH 0.4 to 7.5. Rate measurement was also carried out in temperature ranging from $25^{\circ}C$ to $60^{\circ}C$. The hydrolysis of pipethanate is found to be of first order with respect to pipeethanate concentration over an experimental range of hydrogen ion concentration (pH 0407.5). The apparent activation energy(Ea) at pH 7.5 is 18.30 Kcal/mole and the frequency factor is $1.1408 {\times}10^{9}sec^{-1}$. The rate of the hydrolysis has a minimum at pH 2.5-3.5. In this region the half-life of pipethanate was about15.3 days at $60^{\circ}C$. The catalytic effect of water was found to be $K_{H_2O}$ = $3.16{\times}10^{-5}min^{-1}$ at $60^{\circ}C$. The catalytic constants of the hydroxyl ions and hydrogen ions at $60^{\circ}C$ were also found to be $K_{OH}$ = $4.5519{\times}10^{-5}min^{-1}$ and $K_{H}+$ = $1.1568{\times}10^{-2}min^{-1}$, respectively. This reaction appears to be primarily base catalyzed hydrolysis and pipethanate is relatively reluctant toward acid catalyzed hydrolysis. A positive primary salt effect was noted in the solution of phpethanate at pH 7.5 and at $60^{\circ}C$.

• Journal of Pharmaceutical Investigation
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• v.23 no.1
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• pp.41-49
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• 1993

The bioequivalence of two omeprazole enteric-coated products was evaluated in 16 normal male volunteers (age 26-32 yr, body weight 57-75 kg) following single oral administration. Test product was enteric-coated KD-182 tablet (Chong Kun Dang Corp., Korea) and reference product was $Rosec^{\circledR}$ capsule containing enteric-coated pellets of omeprazole (Yuhan Corp., Korea). Both products contain 20 mg of omeprazole. One tablet or capsule of the test or the reference product was administered to the volunteers, respectively, by randomized two period cross-over study ($2\;{\times}\;2$ Latin square method). Average drug concetrations at each sampling time and pharmacokinetic parameters calculated were not significantly different between two products(p>0.05); the area under the concentrationtime curve to last sampling time (8 hr) $(AUC_{0-8hr})$ $(1946.5{\pm}675.3\;vs\;2018.3{\pm}761.6\;ng{\cdot}hr/ml)$, AUC from time zero to infinite $(AUC_{o-\infty})$ $(2288.6{\pm}1212.8\;vs\;2264.9{\pm}1001.3\;ng{\cdot}hr/ml)$, maximum plasma concentration $(C_{max})$ $(772.5{\pm}283.3\;vs\;925.8{\pm}187.7\;ng/ml)$, time to maximum plasma concentration $(T_{max})$ $(2.38{\pm}1.06\;vs\;2.34{\pm}1.09\;hr)$, apparent elimination rate constant $(k_{\ell})$ $(0.5339{\pm}0.2687\;vs\;0.5769 {\pm}0.2184\;hr^{-I})$, apparent absorption rate constant $(k_a)$ $(1.1536{\pm}0.5278\;vs\;0.9739{\pm}0.9507 hr^{-1})$ and mean residence time (MRT) $(3.13{\pm}0.73\;vs \;3.41{\pm}1.04\;hr)$. The differences of mean $(AUC_{0-8hr})$, $C_{max}$, $T_{max}$ and MRT between the two products (3.69, 19.83, 1.32 and 8.99%, respectively) were less than 20%. The power $(1-{\beta})$ and treatment difference $(\triangle)$ for $AUC_{o-8hr}$ $C_{max}$ and MRT were more than 0.8 and less than 0.2, respectively. Although the power for $T_{max}$ was under 0.8, $T_{max}$ of the two products was not significantly different each other(p>0.05). These results suggest that the bioavailability of KD-182 tablet is not significantly different from that of $Rosec^{\circledR}$ capsule. Therefore, two products are bioequivalent based on the current results.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.8
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• pp.743-752
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• 2013

This is the second paper on the combustion characteristics of landfill gas in a constant volume combustion chamber for a large displacement volume commercial engine, and it discusses the combustion process on the basis of pressure measurements. The results show that the bimodal peak pressure phenomenon, which is caused by the interaction of the heat release and the heat transfer, is more apparent as the mixtures are more favorable to combustion, and the magnitudes of the pressures depend on the unburned fraction. In addition, there exist four main inflection points during heat release owing to variations in the heat transfer area related to flame propagation from the ignition point. Furthermore, the number of inflection points increases as the mixture quality worsens because of the extended burn duration. Consequently, the sophisticated interactions between the heat transfer area changing pattern due to flame propagation and transfer duration might cause very peculiar heat release patterns.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.9
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• pp.1407-1414
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• 2014

Physicochemical properties of rice-based expanded snacks extruded with rice flour, high amylose starch, and isolated soy protein were investigated using a twin-screw extruder. The ingredients were extruded at various feed moisture contents (19~23%) and screw speeds (200~400 rpm) at a constant feed rate (43.4 kg/hr). Bulk density and apparent density of rice snacks were 0.06~0.21, and 0.55~0.65 respectively. Bulk density, apparent density, water absorption index, and breaking strength of rice snacks increased with increasing feed moisture content and decreasing screw speed. However, expansion and water solubility index of rice snacks increased with decreasing feed moisture content and increasing screw speed. Hunter's color L values of rice snacks was lower with increasing screw speed at feed moisture contents of 19% and 21%, but was not significantly different from a feed moisture content of 23%. On the other hand, a and b values of rice snacks were higher with increasing screw speed a feed moisture content of 19%. X-ray diffraction intensity of rice snacks decreased with decreasing feed moisture content and increasing screw speed. X-ray diffraction of rice snacks was V-type at feed moisture contents of 19% and 21% and screw speeds of 300, and 400 rpm. In the microstructure of the cross section of rice snacks, air cells in rice snacks were not well formed, and cell walls were thicker with increasing feed moisture content and decreasing screw speed.

• Bulletin of the Korean Chemical Society
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• v.35 no.5
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• pp.1379-1384
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• 2014

${\alpha}-Fe_2O_3$ spherical particles having an average diameter of ca. 420 nm and ${\alpha}-Fe_2O_3$ fine particles (< 10 ${\mu}m$ particle size) were prepared to examine as catalysts for CO oxidation. Kinetic studies on the catalytic reactions were performed in a flow reactor using an on-line gas chromatography system operated at 1 atm. The apparent activation energies and the partial orders with respect to CO and $O_2$ were determined from the rates of CO disappearance in the reaction stage showing a constant catalytic activity. In the temperature range of $150-275^{\circ}C$, the apparent activation energies were calculated to be 13.7 kcal/mol on the ${\alpha}-Fe_2O_3$ spherical submicron clusters and 15.0 kcal/mol on the ${\alpha}-Fe_2O_3$ fine powder. The Pco and $Po_2$ dependencies of rate were investigated at various partial pressures of CO and $O_2$ at $250^{\circ}C$. Zero-order kinetics were observed for $O_2$ on both the catalysts, but the reaction order for CO was observed as first-order on the ${\alpha}-Fe_2O_3$ fine powder and 0.75-order on the ${\alpha}-Fe_2O_3$ spherical submicron clusters. The catalytic processes including the inhibition process by $CO_2$ on the ${\alpha}-Fe_2O_3$ spherical submicron powder are discussed according to the kinetic results. The catalysts were characterized using XRD (X-ray powder diffraction), FE-SEM (field emission-scanning electron microscopy), HR-TEM (high resolution-transmission electron microscopy), and $N_2$ sorption measurements.

• Asian-Australasian Journal of Animal Sciences
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• v.14 no.12
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• pp.1712-1718
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• 2001

An experiment was carried out to study the effect of monensin administration on mammary functions in crossbred Holstein cattle. Fourteen non-pregnant late lactating crossbred Holstein cattle, approximately 270 days postpartum, were selected for the experiment. They were divided into two groups of 7 animals each. Seven animals in the treated group were given sodium monensin orally in a slow-release capsule. Animals in both control and treated groups were fed the similar diet to maintain milk production and body score at 2.5. Rice straw was fed as a source of dietary fiber throughout the experimental period. After monensin administration, a significant increase in the molar percent of ruminal propionate (p<0.05) and a significant decrease in the molar percent of ruminal acetate (p<0.05) were apparent in comparison to the pretreated period. The ratio of acetate to propionate concentration decreased significantly after monensin administration (p<0.05), while it was maintained at the similar level throughout the period of experiment in the control group. Monensin did not affect the molar percent of ruminal butyrate and valerate. The concentration of milk allantoin between the control group and monensin treated group was not different. An excretion rate of allantoin in milk decreased in animals treated with monensin (p<0.05). Mammary blood flow did not show significant difference between control and monensin treated groups. The plasma glucose concentration, arteriovenous concentration difference and mammary gland uptake of glucose remained constant in both groups. Milk yield of the later stage of lactation in the control group declined during lactation advance while a tendency to increase in the milk yield was apparent after 21 days monensin administration. Milk compositions for concentration of lactose, fat and protein in both control group and monensin treated group did not change throughout the experimental periods. From these results, it can be concluded that the action of monensin could affect the ruminal fermentation pattern. Monensin could not increase milk yield in the late lactating period.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1996.11a
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• pp.99-113
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• 1996

Taurine, a ${\beta}$-amino acid, plays an important role as a neuromodulator and is necessary for the normal development of the brain. Since de novo synthesis of taurine in the brain is minimal and in vivo studies suggest that taurine does not cross the blood-brain barrier, the blood-cerebrospinal fluid (CSF) barrier is likely to play a role in taurine transport between the central nervous system and the systemic circulation. Therefore, we examined in vivo elimination of taurine from the CSF in the rat to characterize in vivo kinetics of elimination for taurine from the CSF is consistent with the in vitro study. Using a stereotaxic device, cannulaes were placed into the lateral ventricle and the cisterna magna of the rat. Radio-labelled taurine and inulin (a marker of CSF flow) were injected into the lateral ventricle, and the concentrations of the labelled compounds in the CSF were monitored for up to 3 hrs in the cisterna magna. The apparent clearance of taurine from CSF was greater than the estimated CSF flow (p<0.005), indicating that there is a clearance process in addition to the CSF flow. Taurine distribution into the choroid plexus was at least 10 fold higher than that found in other brain areas (e.g., cerebellum, olfactory bulb and cortex). When unlabelled taurine was co-administered with radio-labelled taurine, the apparent clearance of the labeled taurine was reduced (p<0.01), suggesting a saturable disposition of taurine from CSF. Distribution of taurine into the choroid plexus, cerebellum, olfactory bulb and cortex was similarly diminished, indicating that the saturable uptake of taurine into these tissues is responsible for the non-linear disposition. A pharmacokinetic model involving first order elimination and saturable distribution described these data adequately. The Michaelis-Menten rate constant estimated from in vivo elimination study is similar to that obtained in the in vitro uptake experiment Collectively, our results demonstrate that taurine is transported in the choroid plexus via a taurine is cleared from the CSF via a saturable process. This process may be functionally relevant to taurine homeostasis in the brain.

• Resources Recycling
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• v.7 no.4
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• pp.27-34
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• 1998

In this research, the processing control of NiCuZn Ferrite (NCZF) had been studied. NiCuZn Ferrite, which calcined at $700^{\circ}C$ for 3 bours, was ball milled for about 60 hours to ill김ke a size of $0.5\mu\;extrm{m}$ followed by granulation using spray dryer Apparent densincatioo rate and initial permeability of NiCuZn Ferrite with an initial packing density had been investigated as f follows. 1.The relative packing density of NCZF green body increas$\xi$d in the range of 48.6-56.8% with an increased forming pressure of 20-170 MPa. 2. The higher the relative pac퍼ng density of NCZF and the sintering temperature are, the higher the initial densification rate. The increased bulk rlcnsity of NCZF was attributed to the densification rate with decreased open pore and increased closed pore as the relative packing density, sintering temperature, and sinteriog tim$\xi$ increased. 3. The initial P permeability of NCZF with constant composition is logarithmically proportional to the bulk density of NCZF sintered at $875~925^{\circ}C$ for 0-5h, and strongly depended on the relative packing density of NCZF green body. The empirical equation is as f follows; log $\mu$i=$G1{\times}BD$+$G2{\times}RPD$+b(0);where, G1, G2; gradient, B.D: bulk density, RPD; relative packing density, b(0); intercept.

• KSBB Journal
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• v.8 no.3
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• pp.256-265
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• 1993

In this study, it was observed that hydrogen productivity varied with changes of input g1ucose concentration and dilution rate in FBR( Fixed Bed Reactor), and CSTR(Continuous Stirred Tank Reactor). We evaluated and compared reaction rate Parameters and internal external and overall mass transfer resistances of immobilized carrier in both reactors. Apparent $K_m$ decreased with increasing dilution rate in FBR but showed a constant value above $0.4h^{-1}$ of dilution rate in CSTR. The experimental results in FBR showed nearly analogous to those in CSTR, however, the performance of FBR resulted in lower hydrogen productivity and an external effectiveness factor but a higher internal effectiveness factor than in CSTR. The overall effectiveness factor obtained with various input 91ucose concentrations showed similar values in both reactors.