• Applied Biological Chemistry
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• v.44 no.3
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• pp.202-205
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• 2001

The root of Zingiber officinale R. was extracted with 80% aqueous MeOH, and the concentrated extract was fractionated with EtOAc, n-BuOH and water phases. The EtOAc fraction exhibited most potent antioxidant activity among them, and two active compounds were isolated by activity-guided separation using repetitive silica gel column chromatography. On the bases of spectral data and the chemical characteristics, the structure of the compounds were determined as 6-shogaol and 12-shogaol, respectively. The $EC_{50}$ values of them were evaluated as 26.4 ${\mu}M$ and 22.5 ${\mu}M$, respectively, where these values were higher than the commercial antioxidants, such as, BHA, BHT and ${\alpha}-tocopherol$.

• Journal of Applied Biological Chemistry
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• v.56 no.4
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• pp.213-217
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• 2013

Phytochemical studies on the leaves of Ailanthus altissima (Simaroubaceae) have not been reported previously. Thus, the authors isolated and identified secondary metabolites from A. altissima. Dried and powdered leaves were extracted with 80% aqueous methanol, and the concentrated extract was successively partitioned with ethyl acetate, n-butanol, and water. Four flavonoids were isolated from the ethyl acetate fraction through repeated silica gel and octadecyl silica gel column chromatography. Spectroscopic data including NMR, MS, and IR allowed for identification of the chemical structures as quercetin (1), afzelin (2), quercitrin (3), and isoquercitrin (4). This is the first report of the isolation of these compounds from A. altissima. The four isolated flavonoids 1-4 as well as solvent fractions (ethyl acetate, n-butanol, and water), were evaluated for DPPH radical scavenging activity.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.3
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• pp.143-147
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• 2002

Granule cells in dentate gyrus of hippocampus relay information from entorhinal cortex via perforant fiber to pyramidal cells in CA3 region. Their electrical activities are known to be closely associated with seizure activity as well as memory acquisition. Since action potential is a stereotypic phenomena which is based on all-or-none principle of $Na^+$ current, the neuronal firing pattern is mostly dependent on afterpotentials which follows the stereotypic $Na^+$ spike. Granule cells in dentate gyrus show afterdepolarization (ADP), while interneurons in dentate gyrus have afterhyperpolarizaton. In the present study, we investigated the ionic mechanism of afterdepolarization in hippocampal dentate granule cell. Action potential of dentate granule cells showed afterdepolarization, which was characterized by a sharp notch followed by a depolarizing hump starting at about $-49.04{\pm}1.69\;mV\;(n=43,\;mean{\pm}SD)$ and lasting $3{\sim}7$ ms. Increase of extracellular $Ca^{2+}$ from 2 mM to 10 mM significantly enhanced the ADP both in amplitude and in duration. A $K^+$ channel blocker, 4-aminopyridine (4-AP, 2 mM), enhanced the ADP and often induced burst firings. These effects of 10 mM $Ca^{2+}$ and 4-AP were additive. On the contrary, the ADP was significantly suppressed by removal of external $Ca^{2+},$ even in the presence of 4-AP (2 mM). A $Na^+$ channel blocker, TTX (100 nM), did not affect the ADP. From these results, it is concluded that the extracellular $Ca^{2+}$ influx contributes to the generation of ADP in granule cells.

• Journal of Microbiology and Biotechnology
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• v.20 no.7
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• pp.1061-1068
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• 2010

The biological synthesis of nanoparticles has gained considerable attention in view of their excellent biocompatibility and low toxicity. We isolated and purified rhamnolipids from Pseudomonas aeruginosa strain BS-161R, and these purified rhamnolipids were used to synthesize silver nanoparticles. The purified rhamnolipids were further characterized and the structure was elucidated based on one- and two-dimensional $^1H$ and $^{13}C$ NMR, FT-IR, and HR-MS spectral data. Purified rhamnolipids in a pseudoternary system of n-heptane and water system along with n-butanol as a cosurfactant were added to the aqueous solutions of silver nitrate and sodium borohydride to form reverse micelles. When these micelles were mixed, they resulted in the rapid formation of silver nanoparticles. The synthesized nanoparticles were characterized by UV-Visible spectroscopy, transmission electron microscopy, and energy dispersive X-ray spectroscopy (EDS). The nanoparticles formed had a sharp adsorption peak at 410 nm, which is characteristic of surface plasmon resonance of the silver nanoparticles. The nanoparticles were monodispersed, with an average particle size of 15.1 nm (${\sigma}={\pm}5.82$ nm), and spherical in shape. The EDS analysis revealed the presence of elemental silver signal in the synthesized nanoparticles. The formed silver nanoparticles exhibited good antibiotic activity against both Grampositive and Gram-negative pathogens and Candida albicans, suggesting their broad-spectrum antimicrobial activity.

• The Korean Journal of Pesticide Science
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• v.12 no.1
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• pp.43-49
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• 2008

This study is conducted to determine the potential of zerovalent iron (ZVI), pyrolusite and birnessite to remediate water contaminated with chlorothalonil. The degradation rate of chlorothalonil by treatment of ZVI, pyrolusite and birnessite was much higher in low condition of pH. Mixing an aqueous solution of chlorothalonil with 1.0% (w/v) ZVI, pyrolusite and birnessite resulted in 4.7, 13.46 and 21.38 hours degradation half-life of chlorothalonil, respectively. Dechlorination number of chlorothalonil by treaonent of ZVI, pyrolusite and birnessite exhibited 2.85, 1.12 and 1.09, respectively. Degradation products of chlorothalonil by teartment of pyrolusite and birnessite were confirmed as trichloro-1,3-dicyanobenzene and dichloro-1,3-dicyanobenzene which were dechlorinated one and two chlorine atoms from parent chlorothalonil by GC-mass. Degradation products of chlorothalonil by ZVI were identified not only as those by pyrolusite and birnessite but as further reduced chloro-1,3-dicyanobenzene and chlorocyanobenzene.

• Proceedings of the KSRS Conference
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• 2004.10a
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• pp.626-629
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• 2004

Texture imaging, which means texture image creation by co-occurrence relation, has been known as one of useful image analysis methodologies. For this purpose, most commercial remote sensing software provides texture analysis function named GLCM (Grey Level Co-occurrence Matrix). In this study, texture-imaging program for GLCM algorithm is newly implemented in the MS Visual IDE environment. While, additional texture imaging modules based on GLDV (Grey Level Difference Vector) are contained in this program. As for GLCM/GLDV texture variables, it composed of six types of second order texture function in the several quantization levels of 2(binary image), 8, and 16: Homogeneity, Dissimilarity, Energy, Entropy, Angular Second Moment, and Contrast. As for co-occurrence directionality, four directions are provided as $E-W(0^{\circ}),\;N-E(45^{\circ}),\;S-W(135^{\circ}),\;and\;N-S(90^{\circ}),$ and W-E direction is also considered in the negative direction of E- W direction. While, two direction modes are provided in this program: Omni-mode and Circular mode. Omni-mode is to compute all direction to avoid directionality problem, and circular direction is to compute texture variables by circular direction surrounding target pixel. At the second phase of this study, some examples with artificial image and actual satellite imagery are carried out to demonstrate effectiveness of texture imaging or to help texture image interpretation. As the reference, most previous studies related to texture image analysis have been used for the classification purpose, but this study aims at the creation and general uses of texture image for urban remote sensing.

• YAKHAK HOEJI
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• v.36 no.1
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• pp.26-36
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• 1992

The metabolic profile of triprolidine, 2-[1-(4-methylphenyl)-3-(1-pyrrolidinyl-1-propenyl)] pyridine, was determined in rat urine and bile. The free fractions of urinary and biliary extracts were obtained without hydrolysis, and the conjugated fractions of extracts were obtained with enzyme hydrolysis using ${\beta}-glucuronidase$ from Escherichia coli. The mixture of N-methyl-N-trimethylsilyltrifluoroacetamide/trimethylsilyl chloride (100 : 1, v/v) was used to derivatize the extracts and then analyzed by gas chromatography/mass spectrometry. Hydroxymethyltriprolidine, hydroxytriprolidine, triprolidine carboxylic acid, dihydroxytriprolidine 1, dihydroxytriprolidine 2, oxotriprolidine carboxylic acid and unchanged triprolidine were detected in rat urine and bile, which were obtained after oral treatment with triprolidine hydrochloride. The maximum urinary excretion rate of triprolidine and hydroxymethyltriprolidine which were extracted from free fraction was at 1 to 2 hours after drug administration. Hydroxymethyltriprolidine was detected in conjugated fraction, and the maximum urinary excretion rate of that metabolite was at 2 to 3 hours in rat. In rat bile analysis, triprolidine was detected only in free fraction and its biliary excretion rate showed the maximum within 30 minutes after drug administration and decreased continuously thereafter. The excretion percentage of triprolidine and hydroxymethyltriprolidine to the initial dose of the parent drug in bile and urine of rats were all low.

• Nuclear Engineering and Technology
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• v.45 no.6
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• pp.721-730
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• 2013

Within the framework of the ASTRID project, core design studies are being conducted by the CEA with support from AREVA and EDF. The pre-conceptual design studies are being conducted in accordance with the GEN IV reactor objectives, particularly in terms of improving safety. This involves limiting the consequences of 1) a hypothetical control rod withdrawal accident (by minimizing the core reactivity loss during the irradiation cycle), and 2) an hypothetical loss-of-flow accident (by reducing the sodium void worth). Two types of cores are being studied for the ASTRID project. The first is based on a 'large pin/small spacing wire' concept derived from the SFR V2b, while the other is based on an innovative CFV design. A distinctive feature of the CFV core is its negative sodium void worth. In 2011, the evaluation of a preliminary version (v1) of this CFV core for ASTRID underlined its potential capacity to improve the prevention of severe accidents. An improved version of the ASTRID CFV core (v2) was proposed in 2012 to comply with all the control rod withdrawal criteria, while increasing safety margins for all unprotected-loss-of-flow (ULOF) transients and improving the general design. This paper describes the CFV v2 design options and reports on the progress of the studies at the end of pre-conceptual design phase 1 concerning: - Core performance, - Intrinsic behavior during unprotected transients, - Simulation of severe accident scenarios, - Qualification requirements. The paper also specifies the open options for the materials, sub-assemblies, absorbers, and core monitoring that will continue to be studied during the conceptual design phase.

• Journal of the Institute of Electronics and Information Engineers
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• v.54 no.7
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• pp.55-60
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• 2017

This paper is proposed on the transmit Method Finger-Printer Scanning of Mutual Capacitance Touch Screen Panel Using Differential Pulse for improving the security of computer information. This system is composed of differential pulse generator and Ring-Counter, also Supply voltage is 5V. this system generates the Pulse wave which is composed of In-Phase and Out of Phase at 1MHz while period of 2m/s. it is designed and be able to operate four channels. overall power consumption is approximately 78.08nW. This prototype is implemented in 0.25um CMOS Process and Chip area is $870um{\times}880um$.

• The Korean Journal of Food And Nutrition
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• v.26 no.3
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• pp.547-552
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• 2013

Cortex Phellodendri (CP) is derived from the dried bark of Phellodendron amurense. It has been widely used as a drug in traditional Korea medicine for treating diarrhea, jaundice, swelling pains in the knees and feet, urinary tract infections and infections of the body surface. In this study, preparative centrifugal partition chromatography (CPC) was successfully carried out to separate antibacterial compounds from a CP methanol extract. The optimum two-phase CPC solvent system was composed of n-butanol: acetic acid: water (4:1:5 v/v/v). The flow rate of the mobile phase was 3 $m{\ell}/min$ in ascending mode with rotation at 1,000 rpm. The CPC-separated fraction and purification procedures were carried out by preparatory HPLC. Palmatine weas identified by $^1H$, $^{13}C$-nuclear magnetic resonance and electrospray ionization-mass spectroscopy spectral data analysis.