• BMB Reports
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• v.44 no.9
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• pp.590-594
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• 2011

The production of antileukemic enzyme methionine ${\gamma}$-lyase (MGL) in distinctly related bacteria, Citrobacter freundii and in their recombinants expressing the Vitresocilla hemoglobin (VHb) has been studied. This study concerns the potential of Citrobacter freundii expressing the Vitreoscilla hemoglobin gene (vgb) for the methionine ${\gamma}$- liyase production. Methionine ${\gamma}$- liyase production by Citrobacter freundii and its $vgb^-$ and $vgb^+$ bearing recombinant strain was studied in shake-flasks under 200 rpm agitation, culture medium and $30^{\circ}C$ in a time-course manner. The $vgb^+$ and especially the carbon type had a dramatic effect on methionine ${\gamma}$- liyase production. The $vgb^+$ strain of C. freundii had about 2-fold and 3.1-fold higher levels of MGL than the host and $vgb^-$ strain, respectively.

• Journal of the Korean Mathematical Society
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• v.34 no.2
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• pp.293-307
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• 1997

In this paper we present the $L^2$-estimation for the kernel $K_n$ of the remaider term for the Gaussian quadrature with respect to one of four Chebyshev weight functions and the error bound of the type on the contour $$ $\mid$R_n(f)$\mid$ \leq \frac{2\pi}{\sqrt{l(\Gamma)}} max_{z\in\Gamma}$\mid$f(z)$\mid$ (\smallint_\Gamma $\mid$K_n(z)$\mid$^2$\mid$dz$\mid$)^\frac{2}{1}, $$ where $l(\Gamma)$ denotes the length of the contour $\Gamma$.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.439-442
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• 2003

This study was conducted to choose optimal distribution and to estimate properly parameters for the derivation of design rainfall in Gamma Family. Design rainfall derived by Gamma Family Distributions were compared by the Relative Mean Errors(RME) and Relative Absolute Errors(RAE) for the consecutive durations of 1, 3, 6, 12, 24, 36, 48 and 72hr and 65 regions all over the regions except Cheju and Wulreung islands in Korea. Consequently, Design rainfall derived by Indirect Method of Moments in the Log-Pearson Type 3 distribution are seemed to be more reasonable than those of other distributions in Gamma Family.

• Journal of the Korean Ceramic Society
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• v.33 no.10
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• pp.1079-1088
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• 1996

Discontinuous ${\gamma}$-LiAlO2 fibers for fiber-reinforcing MCFC matrixes have been produced by the sol-gel process using the centrifugal spinning apparatus of the Rotary type. Gel fibers could be obtained through spinning of stable LiAlO2 complex polymetric sols under the optimum spinning conditions (hollow-disc rotating velocity 9000 rpm sol feeding rate of 4ml/min flowing N2 temperature of 4$0^{\circ}C$ and flowing N2 pressure of 4 bar). It was found that defect free and densified ${\gamma}$-LiAlO2 fibers with the relative density of 98% and the mean diameter of 4.7${\mu}{\textrm}{m}$ were prepared when the spinned fibers were heat-treated to 100$0^{\circ}C$ on the specified heating schedule. in particular the mean diameter and length of fibers could be controlled by the pressure of flowing N2 and the chopping-sieving method respectively.

• The Journal of Korean Medicine
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• v.36 no.1
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• pp.75-85
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• 2015

Objectives: Type 2 diabetes mellitus is a metabolic disease characterized by insulin resistance and high blood glucose level from progressive insulin secretory defect. The rhizome of Atractylodes japonica Koidz. (AJ) has been used for treatment of retention of water in oriental medicine. The aim of this study is to examine the effects of AJ on type 2 diabetes rats. Methods: Type 2 diabetes was induced by 60% high fat diet and low dose streptozotocin. Rats were divided into 4 groups (n = 6); Nor (normal control group), Con (diabetic group treated with vehicle), Met (diabetic group treated with 200 mg/kg metformin) and AJ (diabetic group treated with 100 mg/kg AJ). The body weights and food intakes were measured during the treatment period. After 4 weeks treatment, blood glucose level, HOMA-IR, and protein expressions of IRS-1, p-IRS-1, PPAR-${\gamma}$, and GLUT4 were measured, and histopathological examination of beta cell was performed. Results: Compared with the control group, blood glucose level and HOMA-IR were reduced in rats treated with AJ. Impaired beta cells in pancreas of rats were recovered and phosphorylation of IRS-1 was increased in rats treated with AJ. And also, protein expressions of PPAR-${\gamma}$ and GLUT4 were increased by treatment of AJ. Conclusions: The results suggest that Atractylodes japonica Koidz. may have anti-diabetic effect on type 2 diabetic rats through regulation of blood glucose level and insulin resistance. Therefore Atractylodes japonica Koidz. may have positive effects on patients with type 2 diabetes.

• Journal of the Korean Mathematical Society
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• v.49 no.5
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• pp.1017-1030
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• 2012

We consider forced second order differential equation with $p$-Laplacian and nonlinearities given by a Riemann-Stieltjes integrals in the form of $$(p(t){\phi}_{\gamma}(x^{\prime}(t)))^{\prime}+q_0(t){\phi}_{\gamma}(x(t))+{\int}^b_0q(t,s){\phi}_{{\alpha}(s)}(x(t))d{\zeta}(s)=e(t)$$, where ${\phi}_{\alpha}(u):={\mid}u{\mid}^{\alpha}\;sgn\;u$, ${\gamma}$, $b{\in}(0,{\infty})$, ${\alpha}{\in}C[0,b)$ is strictly increasing such that $0{\leq}{\alpha}(0)<{\gamma}<{\alpha}(b-)$, $p$, $q_0$, $e{\in}C([t_0,{\infty}),{\mathbb{R}})$ with $p(t)>0$ on $[t_0,{\infty})$, $q{\in}C([0,{\infty}){\times}[0,b))$, and ${\zeta}:[0,b){\rightarrow}{\mathbb{R}}$ is nondecreasing. Interval oscillation criteria of the El-Sayed type and the Kong type are obtained. These criteria are further extended to equations with deviating arguments. As special cases, our work generalizes, unifies, and improves many existing results in the literature.

• Proceedings of the KWS Conference
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• 2002.10a
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• pp.803-808
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• 2002

A computer-aided alloy-designing technique to develop the insert metal for transient liquid phase (TLP) bonding was applied to high aluminum Ni-base superalloys. The main procedure of a mathematical programming method was to obtain the optimal chemical composition through rationally compromising the plural objective performances of insert metal by a grid-search which involved data estimation from the limited experimental data using interpolation method. The objective function Z which was introduced as an index of bonding performance of insert metal involved the melting point, hardness (strength), formability of brittle phases and void ratio (bonding defects) in bond layer as the evaluating factors. The contour maps of objective function Z were also obtained applying the interpolation method. The compositions of Ni-3.0%Cr-4.0%B-0.5%Ce (for ${\gamma}$/${\gamma}$/${\beta}$ type alloy) and Ni3.5%Cr-3.5%B-3%Ti (for ${\gamma}$/${\gamma}$ type alloy) which optimized the objective function were determined as insert metal. SEM observations revealed that the microstructure in bond layers using the newly developed insert metals indicated quite sound morphologies without forming microconstituents and voids. The creep rupture properties of both joints were much improved compared to a commercial insert metal of MBF-80 (Ni-15.5%Cr-3.7%B), and were fairly comparable to those of base metals.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.139-140
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• 2008

In this study, the photocurrent (PC) spectroscopy of undoped p-type CIS layers has been investigated at temperatures ranging from 10 to 293 K. Three peaks, A, B, and C, corresponded to the intrinsic transition from the valence band states off $\Gamma_7$(A), $\Gamma_6$(B), and $\Gamma_7$(C) to the conduction band state $\Gamma_6$, respectively. The crystal field splitting and the spin orbit splitting were found at 0.0059 and 0.2301 eV, respectively, and the temperature dependence of the optical band gap could be expressed by using the empirical equation $E_g$(T) = $E_g$(0) - $(8.57\times10^{-4)T^2$/(T + 129). But the behavior of the PC was different from that generally observed in other semiconductors: the PC intensities decreased with decreasing temperature. From the relation of log $J_{ph}$ vs 1/T, where $J_{ph}$ is the PC density, the dominant level was observed at the higher temperatures. We suggest that in undoped p-type CIS layers, the trapping center limits the PC signal due to native defects and impurities with decreasing temperature.

• Journal of Astronomy and Space Sciences
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• v.36 no.3
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• pp.115-119
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• 2019

This paper is a part of the series on positron annihilation spectroscopy of two-phase diffuse gas-and-dust aggregates, such as interstellar medium and the young remnants of type II supernovae. The results obtained from prior studies were applied here to detect the relationship between the processes of the annihilation of the K-shell electrons and incident positrons, and the effects of these processes on the optical spectra of their respective atoms. Particular attention was paid to the Doppler broadening of their optical lines. The relationship between the atomic mass of the elements and the Doppler broadening, ${\Delta}{\lambda}_D$ (${\AA}$), of their emission lines as produced in these processes was established. This relationship is also illustrated for isotope sets of light elements, namely $^3_2He$, $^6_3Li$, $^7_3Be$, $^{10}_5B$ and $^{11}_5B$. A direct correlation between the ${\gamma}-line$ luminosity ( $E_{\gamma}=1.022MeV$) and ${\Delta}{\lambda}_D$ (${\AA}$) was proved virtually. Qualitative estimates of the structure of such lines depending on the positron velocity distribution function, f(E), were made. The results are presented in tabular form and can be used to set up the objectives of further studies on active galactic nuclei and young remnants of type II supernovae.

• IMMUNE NETWORK
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• v.2 no.1
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• pp.12-18
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• 2002

Interferon-${\gamma}$ (IFN-${\gamma}$) is well known as a potent inducer in monokine induced by IFN-${\gamma}$ (Mig) mRNA expression. Although lipopolysaccharide (LPS) alone is weakly effective on Mig mRNA expression. the stimulation of LPS and IFN-${\gamma}$ (LPS/IFN-${\gamma}$ simultaneously has been shown to synergize to produce a high level of Mig mRNA in mouse peritoneal macrophages. In this study, interleukin-10 (IL-10) was found to suppress the LPS/IFN-${\gamma}$-induced Mig mRNA expression in cell type- and mouse strain-specific fashion, but IFN-${\gamma}$ alone-induced Mig mRNA was unaffected by IL-10 under identical experimental conditions. The IL-10-mediated suppression of LPS/IFN-${\gamma}$-stimulated Mig mRNA expression was dependent on the concentration of IL-10, and was prevented when the agent was added 2 hours after LPS/IFN-${\gamma}$ treatment. The suppressive action of IL-10 was dependent on a protein synthesis. However, IL-10 did not reduce the stability of LPS/IFN-${\gamma}$-induced Mig mRNA. These data may have important implications for a previously unrecognized role for IL-10 as a regulator of synergistic effect of LPS on the IFN-${\gamma}$-induced expression of the Mig gene in macrophages.