• Journal of the Society of Cosmetic Scientists of Korea
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• v.32 no.3 s.58
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• pp.201-208
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• 2006

Propionibacterium acnes have been recognized as pus-forming bacteria triggering an inflammation in acne. The present study was conducted to evaluate antimicrobial activities of Dryopteris crassirhizoma Nakai against these etiologic agents of acne vulgaris and application possibility as a cosmetic resource. D. crassirhizoma crude extract and hexane fraction was prepared and its anti-acne effect against Propionibacterium acnes was investigated with minimum inhibitory concentration (MIC) and paper disk diffusion method. The MIC of D. crassirhizoma crude extract and hexane fraction was 0.008 mg/mL and 0.001 mg/mL, respectively. This implies that D. crassirhizoma extract may be an efficient anti-acne ingredient for cosmetics, as a crude extract. The paper disk diffusion assay showed that its anti-acne effect was similar to that of triclosan. The cytotoxic effect of D. crassirhizoma extract was determined by a colorimetric MTT assay using HaCaT cell line and D. crassirhizoma extract exhibited lower cytotoxic effects. Finally, we examine the stability of D. crassirhizoma extract to temperature and pH. The D. crassirhizoma extract was very stable to high temperatures ($25{\sim}121^{\circ}C$) and to wide pH range ($pH\; 2{\sim}11$), suggesting its utilization for cosmetics.

• Radiation Oncology Journal
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• v.17 no.1
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• pp.70-77
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• 1999

Purpose : The expression of p53, P211WAF/CIP, Bcl-2, and Bax underlying the radiation-induced apoptosis in different pH environments using SCK mammary adenocarcinoma cell line was investigated. Materials and Methods Mammary adenocarcinoma cells of hi) mice (SCK cells) in exponential growth phase were irradiated with a linear accelerator at room temperature. The cells were irradiated with 12 Gy and one hour later, the media was replaced with fresh media at a different pHs. After Incubation at 37Microbioiogy, College of Medicine Dong A University for 0$\~$48 h, the extort of apoptosis was determined using agarose gel electrophoresis and flow cytometry. The progression of cells through the cell cycle after irradiation in different pHs was also determined with flow cytometry. Western blot analysis was used to monitor p53, p211WAFfCIP, Bcl-2, and Bu protein levels. Results : The induction of apoptosis by irradiation in pH 6.6 medium was markedly less than that in pH 7.5 medium. The radiation-induced G2IM arrest in pH 6.6 medium lasted markedly longer than that in pH 7.5 medium. Considerable amounts of p53 and p21 proteins already existed at pH 7.5 and increased the level of p53 and p21 significantly after 12 Gy X-irradiation. An incubation at pH 6.6 after 12 Gy X-irradiation did not change the level of p53 and p21 protein levels significantly. Bcl-2 proteins were not significantly affected by radiation and showed no correlation with cell susceptibility to radiation-induced apoptosis in different pHs. An exposure to 12 Gy of X-rays increased the level of Bax protein at pH 7.5 but at pH 6.6, it was slight. Conclusions : The molecular mechanism underlying radiation-induced apoptosis in dinerent pH environments using SCK mammary adenocarcinoma cell line was dependent of the expression p53 and P211YVAF/CIP proteins. We may propose following hypothesis that an acidic stress augments the radiation-induced G2iM arrest, which inhibiting the irradiated cells undergo post-mitotic apoptosis. The effects of environmental acidity on anti-apoptotic and pro-apoptotic function of Bcl-2 family was unclear in SCK mammary adenocarcinoma cell line.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.95-95
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• 2008

본 연구에서는 SiGe p-MOSFET을 제작하여 I-V 특성과 게이트 길이, $V_D$, $V_G$의 변화에 따른 저주파 노이즈특성을 측정하였다. Si 기판위에 성장한 $Si_{0.88}Ge_{0.12}$으로 제작된 SiGe p-MOSFET의 채널은 게이트 산화막과 20nm 정도의 Si Spacer 층으로 분리되어 있다. 게이트 산화막은 열산화에 의해 70$\AA$으로 성장되었고, 게이트 폭은 $25{\mu}m$, 게이트와 소스/드레인 사이의 거리는 2.5때로 제작되었다. 제작된 SiGe p-MOSFET은 빠른 동작 특성, 선형성, 저주파 노이즈 특성이 우수하였다. 제작된 SiGe p-MOSFET의 ESD 에 대한 소자의 신뢰성과 내성을 연구하기 위하여 SiGe P-MOSFET에 ESD를 lkV에서 8kV까지 lkV 간격으로 가한 후, SiGe P-MOSFET의 I-V 특성과 게이트 길이, $V_D$, $V_G$의 변화에 따른 저주파 노이즈특성 변화를 분석 비교하였다.

• Communications of the Korean Mathematical Society
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• v.10 no.4
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• pp.881-887
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• 1995

Let f be a measurable function on the unit ball B in $C^n$, then we define a maximal function $M_p(f), 1 \leq p < \infty$, by $$ M_p(f)(\zeta ) = \sup_{\delta > 0}(\frac{1}{\sigma(\beta(\zeta, \delta))} \int_{T(\beta(\zeta, \delta))} $\mid$f(z)$\mid$^p \frac{d\nu(z)}{(1-$\mid$z$\mid$^n})^{1/p} $$ where $\sigma$ denotes the surface area measure on S, the boundary of B, and $T(\beta(\zeta, \delta))$ denotes the tent over the ball $\beta(\zeta, \delta)$. We prove that the maximal operator $M_p$ belongs to the Muckenhoupt class $A_1$.

• Journal of the Korean Mathematical Society
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• v.52 no.5
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• pp.1097-1108
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• 2015

In this paper, we investigate p-biharmonic maps u : (M, g) $\rightarrow$ (N, h) from a Riemannian manifold into a Riemannian manifold with non-positive sectional curvature. We obtain that if ${\int}_M|{\tau}(u)|^{{\alpha}+p}dv_g$ < ${\infty}$ and ${\int}_M|d(u)|^2dv_g$ < ${\infty}$, then u is harmonic, where ${\alpha}{\geq}0$ is a nonnegative constant and $p{\geq}2$. We also obtain that any weakly convex p-biharmonic hypersurfaces in space formN(c) with $c{\leq}0$ is minimal. These results give affirmative partial answer to Conjecture 2 (generalized Chen's conjecture for p-biharmonic submanifolds).

• Corrosion Science and Technology
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• v.12 no.2
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• pp.65-78
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• 2013

The present investigation deals with the corrosion inhibition of mild steel in 1M $H_2SO_4$ with 1, 4-dihydro pyridine and its derivatives prepared using microwave activation method. The synthesis of inhibitor was confirmed by IR spectra. The effect of 1, 4-dihydropyridine derivatives on the corrosion inhibition of mild steel in 1M $H_2SO_4$ was studied using weight loss and electrochemical polarization techniques. Influence of temperature (303-333K) and synergistic effect of halide ions ($I^-$, $Br^-$ and $Cl^-$) on the inhibition behaviour was also studied. Corrosion products on the metal surface were analyzed by scanning electron microscopy (SEM) and a possible mechanism of inhibition by the compounds is suggested. Thermodynamic parameters were calculated using weight loss data in order to elaborate the mechanism of corrosion inhibition. Polarization measurements revealed that the studied compounds acted as mixed type inhibitor but slightly anodic in nature. Electrochemical impedance measurements revealed that the compounds were adsorbed onto the carbon steel surface and the adsorption obeyed the Langmuir adsorption isotherm. The synergistic effect of halide ions on the IE increases with increase in concentration. The IE obtained from atomic absorption spectrophotometric studies was found to be in good agreement with that obtained from the conventional weight loss method. SEM revealed the information of a smooth, dense protective layer in presence of the inhibitors.

• Proceedings of the KIEE Conference
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• 2003.07c
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• pp.1935-1937
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• 2003

최근 콜레스테롤 센서는 전극 상에 효소를 고정화 하는 방식을 이용하여 센서의 집적도를 높이는 시도가 이루어지고 있다. 이러한 전극 상의 효소고정화 방식으로 entrapment, cross liking, covalently binding 등이 있다. 본 논문에서는 이러한 효소 고정화 방식-전도성 고분자인 P3MT를 사용하여 entrap시키는 방법과 silanization을 이용한 covalent bonding 시키는 방법-에 따른 전기화학 센서의 감도 특성에 관한 연구를 수행하였다. 전도성 고분자를 사용한 고정화 방법은 cyclic voltammograms으로 scan rate 10 mA/s, potential 0.5-1.3V의 조건하에서 P3MT를 Polymerization하고, 효소 고정화를 위해 chromoampermeter로 potential 0.6V에서 900초 동안 수행하였다. silanization을 이용한 covalent bonding 시키는 방법은 nitric acid로 Pt 전극표면을 산화시키고, APTER로 silanization 공정을 시행하였다. 효소 고정화를 위해 전해질로는 0.1M Phosphate buffer solution을 사용하여 cyclic voltammograms으로 scan rate 50 mA/s 전위 0.0-0.7V의 조건 하에서 수행하였다. 이 결과 전도성 고분자를 이용한 고정화 방법에서의 senstivity가 0.89 ${\mu}A/mM{\cdot}cm^2$이고, silanization을 이용한 효소 고정화 방법에서는 1.51 ${\mu}A/mM{\cdot}cm^2$였다. 이처럼 후자의 방법에서 더 좋은 감도 특성이 나타났다. 따라서, silanization을 이용한 고정화 방법이 센서 제작 방식으로 더 적합하다고 사료된다.

• Microbiology and Biotechnology Letters
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• v.13 no.4
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• pp.355-359
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• 1985

The purified $\beta$-galactosidase from L. sporogenes was most active at pH 7.0 and 6$0^{\circ}C$ with O-nitrophenyl-$\beta$-D-galactopyranoside (ONPG) in 0.05 M phosphate buffer. It was stable over a pH range from 5.0 to 9.0 and lost less than 10％ of its activity after heating for 30 minutes at 6$0^{\circ}C$ and pH 7.0. All the mineral ions examined in this work showed no significant activating effect, whereas L-cysteine exerted a great stimnlatory effect on the enzyme activity at the concentration of 10 mM. The Km values were 1.2 mM for ONPG and 33.3 mM for lactose. Approximately 85％ of lactose in cow's milk, in 10％ skim milk and in 5％ lactose solution was hydrolyzed after 4 hours incubation at 6$0^{\circ}C$ with 2 units of the purified $\beta$-galactosidase per $m\ell$ of the substrate solutions. The $\beta$-galactosidase from L. sporogenes, therefore, is considered to be suitable for hydrolysis of lactose in milk and other dairy products.

• Biomedical Science Letters
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• v.14 no.4
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• pp.243-248
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• 2008

The Forkhead box M1 (FoxM1) has been shown to regulate transcription of cell cycle genes essential for $G_1$-S and $G_2$-M progression, including $p27^{kip1}$. The $p27^{kip1}$ gene is a member of the universal cyclin-dependent kinase inhibitor family. Immunohistochemical studies for FoxM1 and $p27^{kip1}$ were performed in 154 lung cancers (69 squamous cell carcinomas (SCC) and 85 adenocarcinomas (ADC)). Immunoreactivity for FoxM1 and $p27^{kip1}$ were found in 79 (51.3%) and 49 (31.8%) out of 154 cases, respectively. Forty-six (58.2%) of the 79 cases with a positive FoxM1 immunoreactivity showed a negative $p27^{kip1}$ expression in 154 lung cancers. According to histologic type, 22 (53.7%) of the 41 SCC cases with a positive FoxM1 immunoreactivity showed a negative $p27^{kip1}$ expression and 24 (63.2%) of the 38 ADC cases with a positive FoxM1 immunoreactivity showed a negative $p27^{kip1}$ expression. The expression of $p27^{kip1}$ was significantly higher in the SCC than in the ADC (P=0.050). There were no significant associations between the FoxM1 and $p27^{kip1}$ expressions and other clinicopathologic factors. These findings suggest that FoxM1 overexpression may diminish the expression of $p27^{kip1}$ protein in lung cancers. Further studies are needed to define the relation between FoxM1 and $p27^{kip1}$ for examining the mechanisms of tissue-specific FoxM1 expression.

• Journal of the Korean Chemical Society
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• v.54 no.3
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• pp.287-290
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• 2010

In the present work we described oxidative cyclisation of peracetylated lactosyl carbamides with N-phenyl-S-chloro isothiocarbamoyl chloride and structural elucidation of novel peracetylated N-Lactosyl-1,2,4-Thiadiazolidin-3-one hydrochlorides. Antimicrobial activities of the title compounds were determined against bacteria S. aureus, E. coli, P. Vulgaris, P. Aeruginosa and fungi A. Niger, Penicillium.