• Biomolecules & Therapeutics
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• v.19 no.1
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• pp.33-37
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• 2011

Decursin was purified from Angelica gigas Nakai, and its effects on the human Kv1.5 (hKv1.5) currents were recorded in mouse fibroblasts ($Ltk^-$ cells) by whole-cell patch-clamp technique. Decursin inhibited hKv1.5 current in a concentration-dependent manner, with an $IC_{50}$ value of $2.7\;{\mu}M$ at +60 mV. Decursin accelerated the inactivation kinetics of the hKv1.5 channel, and slowed the deactivation kinetics of the hKv1.5 current, resulting in a tail crossover phenomenon. Also, decursin inhibited the hKv1.5 current in a use-dependent manner. These results strongly suggest that decursin is a kind of open-channel blocker of the hKv1.5 channel.

• Proceedings of the Korean Society of Veterinary Pathology Conference
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• 2000.09a
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• pp.30-30
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• 2000

Hepatic fibrosis/cirrhosis is characterized by increased production and deposition of collagen, noncollagenous glycaproteins, and proteoglycans, which mainly compose the extracellular matrix (ECM). Recently, activations of macrophages, myofibroblasts and mast cells are thaught ta be associated with the accumulation of ECM. In order to investigate the kinetics of macrophages, myofibroblasts and mast cells and the relationship between these cells and the accumulation of ECM in carban tetrachloride (CCl$_4$)-injected rat liver, we induced liver cirrhosis of rat by an injection of CCl$_4$ for 14 weeks. (omitted)

• Korean Journal of Food Science and Technology
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• v.25 no.5
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• pp.521-525
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• 1993

To elucidate adsorption of proteins and examine the molecular behavior of protein molecules at interfaces, various proteins at the air-water interface were studied. The adsorption data of bovine serum albumin intermediates indicated that the conformational state of a protein played an important role in adsorption of proteins at interfaces. The adsorption behavior of succinylated beta-lactoglobulin indicated that the increase in the net negative charge of the protein significantly inflenced both the kinetics and thermodynamics of adsorption. The adsorption kinetics of beta-casein showed that the salt that induced break-down of water structure decreased the rate of adsorption.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2005.10a
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• pp.456-459
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• 2005

Continuous cooling transformation behaviors were studied fur low carbon HSLA steels containing three different level $(1\~3\;wt\%)$ of Ni addition. Thermo-mechanical processing (TMP) simulations to construct continuous cooling (CCT) diagram were conducted by using Gleeble system. As cooling rate increased, pearlite, granular bainite, acicular ferrite, bainitic ferrite and lath martensite were transformed from deformed austenite. Fully bainitic microstructure were developed at all cooling rate condition in high Ni containing steel due to hardenability increasing effects of Ni. Ni also influenced the transformation kinetics. At the slowest cooling rate of $0.3^{\circ}C/s$, transformation delayed with decreasing Ni contents because of the diffusion of substitutional alloy elements. However, cooling rate slightly increased to $1^{\circ}C/s$, transformation kinetics accelerated with decreasing Ni contents because nucleation of bainite was sluggish due to hardening of residual austenite.

• Journal of the Korean Society of Tobacco Science
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• v.3 no.2
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• pp.109-114
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• 1981

This experiment was conducted with three varieties (Hicks, Burley 21, Sohyang) and cropping systems (Improved mulching, Mulching, Non mulching) of NC 2326 to analyze growth kinetics by means of growth function involving its velocity and accelerated velocity. The basic growth data were obtained by harvest method at interval of ten days from transplanting to hundred days and analyzed by , regression equation, determinant of matrix, and differentiation. The plot of total dry weight of leaves, stalk and roots per a plant vs. time forms a sigmoid curve and its function fitted logistic satisfactorily. Tobacco plant grows at an accelerated velocity. And growth velocity, symmetric about an inflection point, is proportional to biomass attained and to the difference between biomass attained and the maximum, and to the decrease according to the biomass. Of varieties and cropping systems, the most maximum velocity was 9.58g per day per plant in mulching cultivation of NC 2326 and maximum accelerated velocity was 264mg per $day^2$ per plant in Burley 21.

• Transactions of Materials Processing
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• v.17 no.2
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• pp.117-123
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• 2008

In this study, optimum processing condition of rolled AZ31 Mg alloy was investigated by utilizing processing map and constitutive equation considering microstructure evolution(dynamic recrystallization) occurring during hot-working. A series of mechanical tests were conducted at various temperatures and strain rates to construct a processing map and to formulate the recrystallization kinetics in terms of grain size. Dynamic recrystallization(DRX) was observed to occur at a domain of $250^{\circ}C$ and 1/s(maximum dissipation-efficiency region). The effect of DRX kinetics on microstructure evolution was implemented in a commercial FEM code followed by remapping of the state variables. The volume fraction and grain size of deformed part were predicted using a modified FEM code and were compared with those of actual hot forged part. A good agreement was observed between the experimented results and predicted ones.

• Proceedings of the Korean Society of Toxicology Conference
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• 2006.11a
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• pp.34-45
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• 2006

Chemical toxicants are metabolically converted to numerous metabolites in the body. Toxicokinetic characteristics of metabolites could be therefore used as biomarker of exposure for human risk assessment. Biologically based dose response (BBDR) model was proposed for future direction of risk assessment. However, this area has not been developed well enough for human application. Benzo(a)pyrene (BP), for example, is a well-known environmental carcinogen and may produce more than 100 metabolites and BPDE-DNA adduct, a covalently bound form of DNA with benzo(a)pyrene diolepoxides (BPDES), has been applied to qualitatively or quantitaively estimate human exposure to BP. In addition, di(2-ethylhexyl) phthalate (DEHP), a widely used plasticize. in the polymer industry, is one of endocrine-disrupting chemicals (EDCs) and has been monitored in humans using urinary or serum concentrations of DEHP or its monomer MEHP for exposure and risk assessment. However, it is difficult to estimate the actual level of toxicants using these biomarkers in humans using. This presentation will discuss a methodology of exposure and risk assessment by application of metabolic profiling kinetics.

• Journal of Pharmaceutical Investigation
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• v.26 no.3
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• pp.201-205
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• 1996

Poloxamer, block copolymers of ethylene oxide and propylene oxide was crosslinked by diisocyanates and triisocyanates to form water-swellable, physically strong, rubber-like elastic, high biocompatible polyurethanes. The isocyanate-hydroxyl stoichiometry was kept 1:1, but the crosslinking density was varied. The variations examined were the ratio of diisocyanate and triisocyanate. The delivery of two drugs of different water solubilities from hydrogel matrices was studied. It appeared that the drug nature greatly influenced its release kinetics possibly due to drug-polymer interactions. The release profiles, however, could be modified to a great extent by adjusting the polymer network structure Generally the high crosslinking density was required for prolonged drug delivery.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.6
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• pp.491-494
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• 2004

[ $H_2$ ] uptake into $Pt/MoO_{3}$ was enhanced with an increased calcination temperature. Selective CO pulse chemisorption demonstrated that free Pt surface area was decreased as calcination temperature was increased. Characteristic techniques were dedicated to elucidate the closer contact at adlineation sites between Pt and $MoO_3$ substrates. Calcination resulted in supplying the hydrogen access into more $MoO_3$ particles and controlling the kinetics of hydrogen uptake.

• Food Science and Biotechnology
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• v.18 no.5
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• pp.1293-1297
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• 2009

In this study, drying kinetics of onion slices was examined in a laboratory scale vacuum dryer at an air temperature in a range of $50-70^{\circ}C$. Moisture transfer from onion slices was described by applying the Fick's diffusion model, and the effective diffusivity was calculated. Temperature dependency of the effective diffusivity during drying process obeyed the Arrhenius relationship. Effective diffusivity increased with increasing temperature and the activation energy for the onion slices was estimated to be 16.92 kJ/mol. The experimental drying data were used to fit 9 drying models, and drying rate constants and coefficients of models tested were determined by non-linear regression analysis. Estimations by the page and Two-term exponential models were in good agreement with the experimental data obtained.