• Membrane Journal
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• v.21 no.3
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• pp.290-298
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• 2011

The influence of co-existing gases on the hydrogen permeation was studied through a Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane. The hydrogen permeation characteristics of Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane have been investigated in the pressure range 1-3 bar under pure hydrogen and hydrogen mixture gas with carbon dioxide and carbon monoxide at $450^{\circ}C$. Preliminary hydrogen permeation experiments have been confirmed that hydrogen flux was $5.36mL/min/cm^2$ for a Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane (thick: 0.5 mm) using pure hydrogen as the feed gas. In addition, hydrogen fluxes were 4.46, 5.20, $3.91mL /min/cm^2$ for$V_{53}Ti_{26}Ni_{21}$ alloy membrane using $H_2/CO_2$, $H_2/CO$ and $H_2/CO_2/CO$ as the feed gas respectively. Therefore, the hydrogen permeation flux decreased with decrease of hydrogen partial pressure irrespective of temperature and pressure when $H_2/CO_2$, $H_2/CO$ and $H_2/CO_2/CO$ mixture applied as feed gas respectively and permeation fluxes were satisfied with Sievert's law in different feed conditions. It was found from XRD results after permeation test that the Pd-coated $V_{53}Ti_{26}Ni_{21}$ alloy membrane had good stability and durability for various mixtures feeding condition.

• Korean Journal of Mathematics
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• v.21 no.2
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• pp.203-212
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• 2013

We investigate the existence of solutions of the one-dimensional wave system $$u_{tt}-u_{xx}+{\mu}g(u+v)=f(u+v)\;\;in\;(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,\\v_{tt}-v_{xx}+{\nu}g(u+v)=f(u+v)\;\;in\;(-\frac{\pi}{2},\frac{\pi}{2}){\times}R,$$ with Dirichlet boundary condition. We find them by applying linking inequlaities.

• BMB Reports
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• v.44 no.6
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• pp.405-409
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• 2011

The present study demonstrated that valproic acid (VPA) transcriptionally regulates human GM3 synthase (hST3Gal V), which catalyzes ganglioside GM3 biosynthesis in ARPE-19 human retinal pigment epithelial cells. For this, we characterized the promoter region of the hST3Gal V gene. Functional analysis of the 5'-flanking region of the hST3Gal V gene revealed that the -177 to -83 region functions as the VPA-inducible promoter and that the CREB/ATF binding site at -143 is crucial for VPA-induced expression of hST3Gal V in ARPE-19 cells. In addition, the transcriptional activity of hST3Gal V induced by VPA in ARPE-19 cells was inhibited by SP600125, a c-Jun N-terminal kinase (JNK) inhibitor. In summary, our results identified the core promoter region in the hST3Gal V promoter and for the first time demonstrated that ATF2 binding to the CREB/ATF binding site at -143 is essential for transcriptional activation of hST3Gal V in VPA-induced ARPE-19 cells.

• Biomolecules & Therapeutics
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• v.31 no.2
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• pp.168-175
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• 2023

Tramadol is an opioid analog used to treat chronic and acute pain. Intradermal injections of tramadol at hundreds of millimoles have been shown to produce a local anesthetic effect. We used the whole-cell patch-clamp technique in this study to investigate whether tramadol blocks the sodium current in HEK293 cells, which stably express the pain threshold sodium channel Na_v1.7 or the cardiac sodium channel Na_v1.5. The half-maximal inhibitory concentration of tramadol was 0.73 mM for Na_v1.7 and 0.43 mM for Na_v1.5 at a holding potential of -100 mV. The blocking effects of tramadol were completely reversible. Tramadol shifted the steady-state inactivation curves of Na_v1.7 and Na_v1.5 toward hyperpolarization. Tramadol also slowed the recovery rate from the inactivation of Na_v1.7 and Na_v1.5 and induced stronger use-dependent inhibition. Because the mean plasma concentration of tramadol upon oral administration is lower than its mean blocking concentration of sodium channels in this study, it is unlikely that tramadol in plasma will have an analgesic effect by blocking Na_v1.7 or show cardiotoxicity by blocking Na_v1.5. However, tramadol could act as a local anesthetic when used at a concentration of several hundred millimoles by intradermal injection and as an antiarrhythmic when injected intravenously at a similar dose, as does lidocaine.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.21 no.6
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• pp.21-34
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• 2011

VANET offers variety of services to allow safe and comfortable driving through V2V and V2I communications in transportation systems. To use these services, safe and reliable V2V and V2I communications must be guaranteed. In this regards, many RSU-based studies have been carried out to meet certain issues such as: efficiency of frequent communication between RSU and vehicles, security of stored information in RSU, and invasion on vehicle's privacy. In this paper, a scheme is proposed to reduce the dependency on RSU and to enhance the vehicle privacy by using signature-based authentication protocol. The proposed protocol is more efficient than existing protocol with group signature, and satisfies all the requirements of VANET.

• Korean Journal of Plant Resources
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• v.32 no.4
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• pp.290-295
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• 2019

This study was carried out to select the optimal condition for prothallus propagation and sporophyte formation of Leptogramma pozoi (Lag.) Ching subsp. mollissima (Fisch. ex Kunze) Nakaike and to provide basic data for mass production system. In the propagation, 300 mg of prothallus were inoculated in different kinds of medium [1/4, 1/2, Murashige and Skoog (MS), Knop], sucrose (0, 1, 2, 3, 4%), and cultured for 8 weeks. Sporophyte formation studies were carried out by inoculating blended prothallus into artificial soils. The soils were mixed with horticultural substrate, peatmoss, perlite, and decomposed granite at different ratios or only with the horticultural substrate. Then the prothallus was cultivated for 12 weeks to figure out the formation and growth of the sporophytes. The growth and development of prothalli were excellent on MS medium. According to medium components, prothallus growth was favorable in all treatments except 0% sucrose treatment and the highest in 2% sucrose. In the experiment of soil mixtures, sporophyte formation was the highest in the horticultural substrate:perlite 2:1 (v:v) and horticultural substrate:decomposed granite 2:1 (v:v) treatment, and the overall growth was good in the horticultural substrate:decomposed granite 2:1 (v:v) mixed soil.

• Proceedings of the Korean Society of Life Science Conference
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• 2008.10a
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• pp.53.1-53.1
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• 2008

• Proceedings of the Korean Magnestics Society Conference
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• 2007.05a
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• pp.77.1-77.1
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• 2007

• Journal of Microbiology and Biotechnology
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• v.21 no.9
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• pp.903-913
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• 2011

Vibrio parahaemolyticus, which causes gastroenteritis, wound infection, and septicemia, has two sets of type III secretion systems (TTSS), TTSS1 and TTSS2. A TTSS1-deficient vcrD1 mutant of V. parahaemolyticus showed an attenuated cytotoxicity against HEp-2 cells, and a significant reduction in mouse lethality, which were both restored by complementation with the intact vcrD1 gene. V. parahaemolyticus also triggered phosphorylation of mitogen-activated protein kinases (MAPKs) including p38 and ERK1/2 in HEp-2 cells. The ability to activate p38 and ERK1/2 was significantly affected in a TTSS1-deficient vcrD1 mutant. Experiments using MAPK inhibitors showed that p38 and ERK1/2 MAPKs are involved in V. parahaemolyticus-induced death of HEp-2 cells. In addition, caspase-3 and caspase-9 were processed into active forms in V. parahaemolyticus-exposed HEp-2 cells, but activation of caspases was not essential for V. parahaemolyticus-induced death of HEp-2 cells, as shown by both annexin V staining and lactate dehydrogenase release assays. We conclude that secreted protein(s) of TTSS1 play an important role in activation of p38 and ERK1/2 in HEp-2 cells that eventually leads to cell death via a caspase-independent mechanism.

• Bulletin of the Korean Mathematical Society
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• v.50 no.1
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• pp.37-56
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• 2013

This paper deals with the behavior of positive solutions to the following nonlocal polytropic filtration system $$\{u_t=(\mid(u^{m_1})_x{\mid}^{{p_1}^{-1}}(u^{m_1})_x)_x+u^{l_{11}}{{\int_0}^a}v^{l_{12}}({\xi},t)d{\xi},\;(x,t)\;in\;[0,a]{\times}(0,T),\\{v_t=(\mid(v^{m_2})_x{\mid}^{{p_2}^{-1}}(v^{m_2})_x)_x+v^{l_{22}}{{\int_0}^a}u^{l_{21}}({\xi},t)d{\xi},\;(x,t)\;in\;[0,a]{\times}(0,T)}$$ with nonlinear boundary conditions $u_x{\mid}{_{x=0}}=0$, $u_x{\mid}{_{x=a}}=u^{q_{11}}u^{q_{12}}{\mid}{_{x=a}}$, $v_x{\mid}{_{x=0}}=0$, $v_x|{_{x=a}}=u^{q21}v^{q22}|{_{x=a}}$ and the initial data ($u_0$, $v_0$), where $m_1$, $m_2{\geq}1$, $p_1$, $p_2$ > 1, $l_{11}$, $l_{12}$, $l_{21}$, $l_{22}$, $q_{11}$, $q_{12}$, $q_{21}$, $q_{22}$ > 0. Under appropriate hypotheses, the authors establish local theory of the solutions by a regularization method and prove that the solution either exists globally or blows up in finite time by using a comparison principle.