• Journal of Pharmaceutical Investigation
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• v.13 no.4
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• pp.173-182
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• 1983

The influence of prazosin (0.1 mg/kg i.v.) on the excretion and diuretic action of furosemide (2mg/kg i.v.) in rabbits was studied to investigate an interaction between ${\alpha}-adrenergic$ blocking agent, prazosin and furosemide. The results were as follows; 1) With the combined administration of prazosin and furosemide, the plasma concentration of furosemide was increased, the urinary excretion rate and renal clearance of furosemide were reduced, and tile biological half-life of furosemide was increased. 2) The diuretic action of furosemide was significantly reduced with the combined administration of prazosin: maximal decrease in urine volume, urinary electrolytes, clearance of $Na^+$ and $Cl^-$, and GFR and RPF, as well as maximal increase in $Na^+$ reabsorption rate were noted 10 minutes after administration of furosemide (2mg/kg i.v.)

• Journal of Embryo Transfer
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• v.10 no.3
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• pp.243-250
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• 1995

Frozen storage of the oocytes has been used in a few mammalian species including mouse, hamster, human and cattle. However, frozen4hawed oocvtes show different sperm penetration on the levels of the zona pellucida and the plasma memhrane when compared with fresh oocytes. To elucidate biological changes occurring during freezing and thawing, we examined the kinetics of sperm penetration into frozen-thawed hamster oocytes. Oocytes obtained from superovulated female golden hamsters were frozen-thawed in an autofreezer according to an established method. Fresh and frozen4hawed oocytes were fertilized in vitro with capacitated hamster spermatozoa after removing the zona pellucida. The oocytes were examined at 1, 2, 3 and 6 h postinsemination. Sperm penetration found to be 1 h delayed in frozen-thawed oocytes. Other parameters such as degree of polyspermy and decondensing sperm heads were not affected by freezing and thawing. The results suggest that freezing and thawing may cause changes in the egg membrane surface and subsequently which leads to delay in the sperm-egg fusion.

• Food Science and Biotechnology
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• v.16 no.6
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• pp.954-957
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• 2007

Gelation mechanism of xanthan-carob mixture (X/C) was investigated based on thermorheological behavior. Three X/C ratios (1:3, 1:1, and 3:1) were studied. Small amplitude oscillatory shear tests were performed to measure linear viscoelastic behavior during gelation. Temperature sweep ($-1^{\circ}C/min$) experiments were conducted. Using a non-isothermal kinetic model, activation energy (Ea) during gelation was calculated. At 1% total concentration, the Ea for xanthan fraction (${\phi}_x$)=0.25, 0.5, and 0.75 were 178, 159, and 123 kJ/mol, respectively. However, a discontinuity was observed in the activation energy plots. Based on this, two gelation mechanisms were presumed-association of xanthan and carob molecules and aggregation of polymer strands. The association process is the primary mechanism to form 3-D networks in the initial stage of gelation and the aggregation of polymer strands played a major role in the later stage.

• Journal of Microbiology and Biotechnology
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• v.26 no.2
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• pp.255-262
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• 2016

The carrageenan-degrading marine bacterium Vibrio sp. strain NJ-2 was isolated from rotten red algae, and κ-carrageenase with high activity was purified from the culture supernatant. The purified enzyme with molecular mass of 33 kDa showed the maximal activity of 937 U/mg at 40℃ and pH 8.0. It maintained 80% of total activity below 40℃ and between pH 6.0 and 10.0. The kinetics experiment showed the K_m and V_max values were 2.54 g/ml and 138.89 mmol/min/mg, respectively. The thin layer chromatography and ESI-MS analysis of hydrolysates indicated that the enzyme can endolytically depolymerize the κ-carrageenan into oligosaccharides with degrees of depolymerization of 2-8. Owing to its high activity, it could be a valuable tool to produce κ-carrageenan oligosaccharides with various biological activities.

• KSBB Journal
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• v.17 no.1
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• pp.1-13
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• 2002

Label-free optical methods for the monitoring of interactions between biological molecules have become increasingly popular within the last decade. A rising number of publications have demonstrated the benefits of direct biomolecular interaction analysis(BIA) for biology and biochemistry, such as antigen-antibody Interactions, receptor-ligand interactions, protein-DNA, DNA- intercalator, and DNA-DNA interactions. This article gives an overview of the historical development, principle and application of label-free optical biosensor to examine the functional characteristics of biospecific interaction, such as kinetics, affinity, and binding position of biomolecular between an immobilized species at the transducer surface and its dissolved binding partner.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.268-272
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• 2002

Kinetic experiments on the biological oxidation of $Fe^{2＋}$ by Acidithiobacillus ferrooxidans were conducted by measuring the total organic carbon content. The total organic carbon in the solution was determined with different initial concentrations of $Fe^{2＋}$(4, 9, 15, and 20 mg/ml). The growth of At. ferrooxidans and substrate utilization were described by the Monod expression. The total organic carbon was found to be an indicator of the biomass concentration and thus may be effectively utilized for estimating cell growth rates in kinetic model development.

• Journal of Microbiology and Biotechnology
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• v.12 no.2
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• pp.292-295
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• 2002

A chromate-resistant white rot fungus, Inonotus cuticularis, abundant in oak trees, was isolated for chromate removal and detoxification of chromate. Inonotus cuticularis was also investigated for an optimal waste treatment system. The screened cells were able to reduce an initial chromate concentration of as high as 1,300 ppm. Cell growth kinetics showed that the optimum culture conditions in flasks were at $33^{\circ}C$ and pH 4.2. Furthermore, the cells were able to remove $54\%$ of the initial chromate by a two-stage operation based on the combination of a fermentor and airlift reactor.

• Proceedings of the KOSOMBE Conference
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• v.1996 no.05
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• pp.339-342
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• 1996

Vertical ground reaction forces on a treadmill were measured at different walking speeds using two tandem force plates. Comparing vertical ground reaction forces in treadmill walking with those in ground free walking, treadmill walking overestimated the first and second peak forces. With the increase of the walking speed, this phenomenon becomes more significant. In treadmill running, the first peak force reached 210-280% of the body weight. However, the instrumented treadmill showed a great potential to investigate the kinetics for multiple foot-strike measurements.

• Journal of Korean Society on Water Environment
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• v.23 no.5
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• pp.689-696
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• 2007

Kinetic analysis was important to develope the biological nutrient removal process effectively. In this research, anoxic-anaerobic-aerobic system was operated to investigate kinetic behavior on the nutrient removal reaction. Nitrification and denitrification were important microbiological reactions of nitrogen. The kinetics of organic removal and nitrification reaction have been investigated based on a Monod-type expression involving two growth limiting substrates : TKN for nitrification and COD for organic removal reaction. The kinetic constans and yield coefficients were evaluated for both these reactions. Experiments were conducted to determine the biological kinetic coefficients and the removal efficiencies of COD and TKN at five different MLSS concentrations of 5000, 4200, 3300, 2600, and 1900 mg/L for synthetic wastewater. Mathematical equations were presented to permit complete evaluation of the this system. Kinetic behaviors for the organic removal and nitrification reaction were examined by the determined kinetic coefficient and the assumed operation condition and the predicted model formulae using kinetic approach. The conclusions derived from this experimental research were as follows : 1. Biological kinetic coefficients were Y=0.563, $k_d=0.054(day^{-1})$, $K_S=49.16(mg/L)$, $k=2.045(day^{-1})$ for the removal of COD and $Y_N=0.024$, $k_{dN}=0.0063(day^{-1})$, $K_{SN}=3.21(mg/L)$, $k_N=31.4(day^{-1})$ for the removal of TKN respectively. 2. The predicted kinetic model formulae could determine the predicted concentration of the activated sludge and nitrifier, investigate the distribution rate of input carbon and nitrogen in relation to the solid retention time (SRT).

• Journal of the Korean Electrochemical Society
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• v.12 no.1
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• pp.11-25
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• 2009

Fuel cells are expected to be one of the major clean new energy sources in the near future. However, the slow kinetics of electrocatalytic hydrogen oxidation reaction (HOR) and oxygen reduction reaction (ORR), and the high loading of Pt for the anode and cathode material are the urgent issues to be addressed since they determine the efficiency and the cost of this energy source. In this review paper, a new approach was developed for designing electrocatalysts for the HOR and ORR in fuel cells. It was found that the electronic properties of Pt could be fine-tuned by the electronic and geometric effects introduced by the substrate alloy metal and the lateral effects of the neighboring metal atoms. The role of substrate was found reflected in a volcano plot for the HOR and ORR as a function of their calculated d-band centers. This paper demonstrated a viable way to designing the electrocatalysts which could successfully alleviate two issue facing the commercializing of the fuel cell-the cost of electrocatalysts and their efficiency.