• Biotechnology and Bioprocess Engineering:BBE
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• 제9권4호
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• pp.256-260
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• 2004

Melanin was decolorized by lignin peroxidase from Phanerochaete chrysosporium. This decolorization reaction showed a Michaelis-Mentens type relationship between the decolorization rate and concentration of two substrates: melanin and hydrogen peroxide. Kinetic constants of the decolorization reaction were 0.1 OD$\sub$475//min ($V_{max}$) and 99.7 mg/L ($K_{m}$) for melanin and 0.08 OD$\sub$475//min ($V_{max}$) and 504.9 ${\mu}$M ($K_{m}$) for hydrogen peroxide, respectively. Depletion of hydrogen peroxide interrupted the decolorization reaction, indicating the essential requirement of hydrogen peroxide. Pulsewise feeding of hydrogen peroxide continued the decolorizing reaction catalyzed by lignin peroxidase. These results indicate that enzymatic decolorization of melanin has applications in the development of new cosmetic whitening agents.

• 대한치과기공학회지
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• 제33권3호
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• pp.219-224
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• 2011

Purpose: The current study focused on investigating color change of dental zirconia block with respect to the block coloring time. Methods: Three types of dental zirconia blocks(Zirtooth, Pearl-HT, D-Max) were tinted with coloring agent under four different time condition (0 minutes, 1 minutes, 10 minutes, 30 minutes). The quantitative evaluation of the tinted dental zirconia blocks was conducted with spectrophotometer. Results: The Zirtooth and D-Max blocks showed lower H value. The Pearl-HT blocks showed poor reflectivity(L value). Conclusion: The study of color change of zirconia block, which consists the substructure of all ceramic Crown, is applicable for deciding appropriate coloring condition when fabricating one layer ceramic Crown or double layer ceramic Crown.

• 천문학회지
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• 제29권spc1호
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• pp.271-272
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• 1996

Assuming that particles can be accelerated to high energies via diffusive shock acceleration process at the accretion shocks formed by the infalling flow toward the clusters of galaxies, we have calculated the expected spectrum of high-energy protons from the cosmological ensemble of the cluster accretion shocks. The model with Jokipii diffusion limit could explain the observed cosmic ray spectrum near $10^{19}eV$ with reasonable parameters and models if about $10^{-4}$ of the infalling kinetic energy can be injected into the intergalactic space as the high energy particles.

• 약학회지
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• 제40권1호
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• pp.65-71
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• 1996

Characterization of Polyphenol oxidase (PPO) in Perillae Folium, particullarly inhibitor studies were investigated. This enzyme was stable at pH 5.0 and the residual activity of PPO at ${\geq}$ ph 5.5 was estimated to be very low. PPO activity was decreased slightly by adding amino acid with catechol as a substrate, particullary PPO activity was inhibited markedly by cystein, histidine, lysine and arginine. In the absorption spectra of the product formed when catechol was oxidized by PPO, with a ${\lambda}_{max}$ at 410nm, the peak shifted toward ${\lambda}_{max}$ 520nm by addition of L-proline. At relatively low concentrations($10^{-3}M$), sulfite and dithiothreithol completely inhibited PPO activity. Inhibition of PPO activity by amino acids and inhibitors increased or decreased depending on the pH used to measure it.

• 약학회지
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• 제47권6호
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• pp.444-459
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• 2003

Ethosuximide is an oral anticonvulsantic agent used in the first choice anti-absence seizure drug. The purpose of this study was to assess the pharmacokinetic profile of the ethosuximide in healthy Korean volunteers and to develop the efficient assay method of ethosuximide in human plasma. The pharmacokinetics of ethosuximide administered orally was evaluated after a dose of 500 mg. Ethosuximide was assayed from plasma by a specific HPLC method reading absorbance at 195 nm. AUC was 1222$\pm$160 $\mu\textrm{g}$/$m\ell$$.$hr, $C_{max}$ 14.2l$\pm$1.74 $\mu\textrm{g}$/$m\ell$, $T_{max}$ 1.06$\pm$0.62 hr and half-life 77.83$\pm$12.46 hr. The half-life in Korean was longer than, in Caucasian (53∼56 hr).).).

• 약학회지
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• 제57권6호
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• pp.442-447
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• 2013

The aim of the present study was to improve commercial twice-a-day Acebrophylline formulation to once-a-day new formulation to improve patient compliances. To develop the double-layered tablet, the sustained release layer was prepared using Eudragit$^{(R)}$ L100-55 and Carnauba wax. The sustained release layer has shown delayed release rates in pH 1.2 which comparable to that of performed in pH 6.8 buffer. In the comparative pharmacokinetic study with commercialized Surfolase$^{(R)}$, the present double-layered Acebrophylline tablet has shown similar pharmacokinetic parameters of AUC, $C_{max}$ and $T_{max}$ values.

• 생명과학회지
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• 제7권4호
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• pp.355-357
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• 1997

대립종자와 소립종자의 cross부터 F$_{2}$와 F$_{3}$ 세대에서의 종자크기에 대한 빈도분포의 다음과 같다. 두 세대에서 모본의 크기와 같은 progeny는 나타나지 않았으며 각 세대의 평균치는 양 모본의 평균치 보다 낮았다. 소립종자 크기에 비해 우성적인 유전양상을 나타 내었다.

• Journal of Magnetics
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• 제9권3호
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• pp.75-78
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• 2004

Magnetic transmission soft X-ray microscopy has been used to study element-specifically the magnetization reversal behavior of ${(Co_{84}Cr_{16})}_{87}Pt_{l3}$ alloy thin films with a lateral resolution of 35 nm. Our results indicate that the magnetization switching is carried out by a random nucleation process that can be attributed to the reversal of individual grains. We found evidence of a large distribution of the switching fields at the nanogranular length scale, which has to be considered seriously for applications of CoCrPt systems as magnetic high density storage materials.

• Korean Journal of Mathematics
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• 제29권4호
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• pp.775-784
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• 2021

For the polynomial P(z) of degree n and having all its zeros in |z| ≤ k, k ≥ 1, Jain [6] proved that $${{\max\limits_{{\mid}z{\mid}=1}}\;{\mid}P^{\prime}(z){\mid}{\geq}n\;{\frac{{\mid}c_0{\mid}+{\mid}c_n{\mid}k^{n+1}}{{\mid}c_0{\mid}(1+k^{n+1})+{\mid}c_n{\mid}(k^{n+1}+k^{2n})}\;{\max\limits_{{\mid}z{\mid}=1}}\;{\mid}P(z){\mid}$$. In this paper, we extend above inequality to its integral analogous and there by obtain more results which extended the already proved results to integral analogous.

• 한국임상약학회지
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• 제22권1호
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• pp.9-12
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• 2012

Background: Cefcapene pivoxil hydrochloride, is an ester-type oral cephem antibiotic. This study was performed to compare the pharmacokinetics and evaluate the bioequivalence of two cefcapene pivoxil hydrochloride 75 mg formulations. Method: In a randomized $2{\times}2$ crossover study, sixty healthy male volunteers were randomly assigned into two groups. After a single dose of 75 mg cefcapene pivoxil hydrochloride oral administration, blood samples were collected at specific time intervals from 0-12 hours. The plasma concentrations of cefcapene pivoxil hydrochloride were determined by LC-MS/MS. The pharmacokinetic parameters were determined from the plasma concentration-time profiles of both formulations. The pharmacokinetic parameters such as $AUC_{last}$, $AUC_{inf}$ and $C_{max}$, were calculated and the 90% confidence intervals for test/reference ratio for pharmacokinetic parameters were obtained by analysis of variance on logarithmically transformed data. Results: The mean value for $AUC_{last}$ in test and reference drug was $4053.1{\pm}876.5\;ng{\cdot}hr/mL$ and $3595.7{\pm}1029.1\;ng{\cdot}h/mL$, respectively. The mean value for $C_{max}$ in test and reference drug was $1324.9{\pm}321.4$ ng/mL and $1159.1{\pm}335.9$ ng/mL, respectively. The 90% confidence intervals of the $AUC_{last}$ and $C_{max}$ ratio for test drug and reference drug were log 1.09-log1.22 and log 1.09-log1.24, respectively. No adverse events were reported by subjects or found on analysis of vital signs or laboratory tests. Conclusion: This single dose study found that the test and reference products met the regulatory criteria for bioequivalence in these health volunteers. Both formulations were safe and well tolerated in 75 mg of cefcapene pivoxil hydrochloride.