• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.06a
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• pp.460-461
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• 2009

We studied the effects of post-annealing treatment on poly(3-hexylthiophene)(P3HT, donor):[6,6]-phenyl $C_{61}$ butyric acid methyl ester(PCBM, acceptor) blend film as an active layer in the organic solar cells(OSCs). For the formation of the active layer, 3 wt.% P3HT:PCBM solution in chlorobenzene were deposited by spin-coating method. In order to optimize the performance of OSCs, the P3HT crystallization and the redistribution of PCBM cluster at P3HT:PCBM composition as a function of post-annealing condition from room temperature to $200^{\circ}C$ were measured by the Hall effect and the UV-vis Spectrophotometer. We thought that the improved efficiency in the OSCs with post-annealing treatment at $150^{\circ}C$ can be explained by the efficient separation or collection of the photogenerated excitons at donor-acceptor interface by P3HT crystallization.

• 한국생물공학회:학술대회논문집
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• 2001.11a
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• pp.705-708
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• 2001

Enzymatic synthesis and purification of sugar esters using supercritical $CO_2$ were investigated. The observed yield of suagr ester produced by transesterification of methyl glucoside and oleic acid using a lipase(Novozym 435) was 67% at 24 hours of reaction in the supercritical $CO_2$. The solubility of the fatty acids in the supercritical $CO_2$ was measured to find the conditions of supercritical separation of the fatty acids from the reaction mixture. The solubility of capric and oleic acid was 5 ${\times}$ $10^{-4}$, 1.7 ${\times}$ $10^{-4}$ mol/mol $CO_2$, respectively, varying at $35{\sim}50^{\circ}C$ and 80${\sim}$120 atm.

• BMB Reports
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• v.29 no.3
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• pp.225-229
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• 1996

Effects on thrombin by an amphipathic cation, dequalinium, which has been recognized as an anticarcinoma agent were investigated with small chromogenic substrates such as Na-benzoyl-DL-argininep-nitroanilide (BApNA), H-D-phenylalanyl-L-pipecoyl-L-arginine-p-nitroanilide (S-2238), and Na-p-tosyl-L-arginine methyl ester (TAME). Among them, only TAME hydrolysis due to an esterase activity of the enzyme was significantly activated to 81% at 20 ${\mu}M$ dequalinium in the absence of NaCl. This stimulation became even higher in the presence of 0.2 M NaCl to 3.5-fold at 60 ${\mu}M$ dequalinium. This specific activation of thrombin was well correlated with the results of in vitro coagulation tests measuring the activated partial thromboplastin time (APTT) and the prothrombin time (PT) It is pertinent. therefore, to suggest that the esterase activity should be examined in addition to the effects on 5-2238 hydrolysis when especially any regulators not directed to an active site of thrombin need to be studied. We also expect that dequalinium could be a useful tool for studying structure-function relationship of thrombin and blood coagulation.

• Microbiology and Biotechnology Letters
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• v.24 no.4
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• pp.512-518
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• 1996

Eleven strains had been previously isolated from kimchi and identified in our laboratory. The ability of each strain in aroma production was investigated by sensory evaluation. Among them Saccharomyc s sp. YK-17, Saccharomyces sp. YK-18, Saccharomyces sp. YH-3 and Saccharomyces fermentati YK-19 produced fruity flavour. Especially, Saccharomyces fermentati YK-19 produced apple and pineapple-like flavours. Pichia media YK-11, Saccharomyces sp. YK-20 and Pichia chambardii YH-4 produced wine-like flavour. Debaryomyces sp. YK-6, Debarymyces coudertii YK-10, Saccharomyces sp. YK-12 and Pichia haplophilia YH-5 produced alcoholic flavours. Using the good flavour producing strains as starters, various groups of kimchi were fermented, and the sensory characteristics of each group such as odor, taste and total acceptability were evaluated. The acidic odor, moldy odor and taste were reduced by adding starter, while the fresh sourness odor and taste similar to fruity fiavour were increased by starter. Comparing with the control group, these odor, taste and total acceptability were increased in the starter-added groups, such as Pichia edia YK-11, Saccharomyces sp. YK-17, and Saccharomyces,fermentati YK- 19. Saccharomyces fermentati YK-19 added kimchi group was higher siginificantly (P<0.05) than the others at the total acceptability. Volatile compounds of the culture broth of Saccharomyces fermentati YK-19 were analysed by gas chromatography, and 6 species of esters and 4 species of alcohols were identified. Among them, the ester substances which broth largely responsible for the apple-like flavour in the sensory evaluation, were found to be ethyl 2-methyl butvrate, ethyl pentanoate and ethyl acetate.

• Biomedical Science Letters
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• v.16 no.1
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• pp.25-32
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• 2010

Sprague-Dawley(SD) rats were orally administered with $N^G$-nitro-L-arginine methyl ester(L-NAME) which inhibits or blocks the production of nitric oxide from L-arginine in vascular endothelial cells and vessel tissue to statistically examine the effects of nitric oxide on some physiological changes such as blood pressure and heart rate, and to confirm the apoptosis induced by the suppressed nitric oxide activity in some related organs under light microscope. Systolic blood pressure significantly increased 28.5% by the chronic treatment of L-NAME for 8 weeks (P<0.001), no significant difference, however, was observed in heart rate between the control group and the L-NAME-treated group regardless of their age. Hematoxylin-eosin staining showed some histological alterations only in kidney among the examined organs; heart, liver, pancreas, and adrenal gland from the L-NAME-treated group. TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling) test showed a strong positive reaction, representing that the chronic treatment of L-NAME facilitates apoptosis, in the cortex and medulla of kidney, but not any significance detectable in the other organs. These results conclude that chronic treatment of L-NAME significantly increases blood pressure, and that the followed inhibition of nitric oxide synthesis occurs a typical inducement of apoptosis in kidney.

• Korean Journal of Veterinary Research
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• v.42 no.3
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• pp.321-326
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• 2002

The effect of nitric oxide synthase(NOS) inhibita, $N^G$-nitro-L-arginine-methyl ester(L-NAME) and prostanoid synthesis inhibiter, indomethacin on the photorelaxation, when was exposed to the long-wave length UV-light, was examined on the precontraction by the phenylephrine in the isolated pig renal artery. 1. UV-light relaxed both with-endothelium and without-endothelium in the pig renal arterial ring contracted by the phenylephrine. The magnitude of photorelaxation was dependent on the exposure time for UV-light. 2. UV-Iight induced relaxation was inhibited by L-NAME and indomethacin on the precontraction by the phenylephrine in the isolated pig renal artery. 3. UV-Iight induced relaxation was inhibited by methylene blue on the precontraction by the phenylephrine in the isolated pig renal artery. These results suggest that UV-light induced photorelaxation may be due to cGMP involved both nitric oxide and prostanoid on the precontraction by the phenylephrine in the isolated pig renal artery.

• Proceedings of the KIEE Conference
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• 2011.07a
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• pp.1714-1715
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• 2011

In this work, highly conductive organic solvent-based polyaniline(PANI) was used as an anode in organic photovoltaic cells (OPV) based on poly - (3-hexylthiophene) and [6,6] - phenyl - C60 - butyricacid methyl ester (P3HT : PCBM). The transmittance of the used PANI film were 87.67% and 86.57% at 550nm, and its sheet resistance were 454 ${\Omega}/{\Box}$ and 298 ${\Omega}/{\Box}$. We fabricated ITO-free OPV cells using PANI as an anode, which exhibited an external power conversion efficiency of 2.28% with a result of Jsc of 6.922mA/cm2, Voc of 0.6093V, and FF of 54.10% under an illumination of air mass(AM) 1.5G (100mW/$cm^2$). We used ink-jet printing to deposit buffer layer and active layer on a glass substrate.

• BMB Reports
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• v.32 no.6
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• pp.567-572
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• 1999

We have previously shown that a DNA fragment is responsible for the anticoagulatory effect of an earthworm, Lumbricus rubellus. The anticoagluant increased the activated partial thromboplastin time (APTT) and also inhibited the thrombin activity observed with either N-${\alpha}$-p-tosyl-L-arginine methyl ester (TAME) or H-D-phenyl-alanyl-L-pipecoil-L-arginine-p-nitroanilide (S-2238). Since trypsin digestion of the anticoagulant further increased the APTT, the possible presence of a regulatory protein for the anticoagulatory DNA was investigated by digesting the anticoagulant with trypsin and isolating the DNA fragment with C4-reversed phase HPLC. The DNA fragment lacking a regulatory protein was eluted in the flow-through fraction, and analyzed with thrombin and activated factor X. Activated factor X activity was more strongly inhibited than thrombin activity. For DNA digestion, we treated the anticoagulant with DNase and purified the DNA-binding protein with a FPLC Resource-S cation exchange column. The regulatory protein, with an $M_r$ of 55.0 kDa, reduced the anticoagulatory effect of the DNA fragment.

• The Korean Journal of Mycology
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• v.14 no.2
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• pp.101-107
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• 1986

The properties of carboxyl proteinase which was contained in Poria cocos (Schw.) Wolf were investigated by means of the purification with 0.65 ammonium sulfate saturation, DEAE cellulose and Sephadex G-75 gel filtration. This enzyme was found to hydrolyze only peptide bond between glutamyl-L-tyrosine of carbobenzoxy-L-glutamyl-L-tyrosine among the synthetic substrates of carbobenzoxy-L-glutamyl-L-tyrosine, hippuryl- L-phenylalanine and hippuryl-L-arginine. This enzyme was inhibited by $Zn^{+2},\;Fe^{+2},\;Ca^{+2},\;CN^{-1},\;P_2O_7^{-4}$ ions, but stimulated by $Hg^{+2}$ ion. Also, this enzyme was inhibited by organic compounds such as L-lysine, L-phenylalanine, hippuryl-L-phenylalanine, diazoacetyl-DL-norleucine methyl ester (DAN) and 1,2-epoxy-3-(P-nitrophenoxy)propane(EPNP). In particular, the activity was inhibited by L-lysine till 20 minutes of preincubation time rapidly, and by DAN in the presence of $Cu^{+2}$ ion more rapidly after 30 minutes than DAN in the absence of $Cu^{+2}$ ion. L-Lysine was found to be a competitive inhibitor and its $K_i$ value was determined to be 0.12 mmole by Dixon plot.

• Biomolecules & Therapeutics
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• v.19 no.3
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• pp.336-341
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• 2011

As part of an ongoing search for natural plants with antioxidant compounds by measuring the radical scavenging effect on 1,1-diphenyl- 2-picrylhydrazyl (DPPH), a total extract of the twigs of Galium spurium L. (Rubiaceae) was found to show potent antioxidant activity. Subsequent activity-guided fractionation of the methanolic extract led to the isolation of nine compounds, asperulosidic acid methyl ester (1), asperuloside (2), caffeic acid (3), kaempferol-3-O-L-rhamnopyranoside (4), quercetin-3-O-[${\alpha}$-Lrhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside] (5), isorhamnetin-3-O-glucopyranoside (6), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (7), kaempferol-3-O-[${\alpha}$-L-rhamnopyranosyl($1{\rightarrow}6$)-${\beta}$-D-glucopyranoside] (8), and quercetin (9). Their structures were elucidated by spectroscopic studies. Compounds 1, 3-8 were isolated for the first time from this plant. Among them, compounds 3 and 9 showed the significant radical scavenging effects on DPPH, and compounds 3 and 7 showed the potent riboflavin originated superoxide quenching activities.