• Biomolecules & Therapeutics
• /
• 제2권2호
• /
• pp.136-140
• /
• 1994

To prove the hypothesis that NO- and N $O_2$-carrying molecules potentiate photorelaxation by generating NO, investigation was carried out using isolated rabbit and human corpus cavernosum. Corporal smooth muscle, in the presence or absence of endothelium, relaxed only slightly upon ultraviolet light (366 nm) irradiation. But, NO-and/or N $O_2$-containing compounds such as streptozotocin and $N^{G}$-nitro-L-arginine methyl ester significantly (p<0.01) enhanced photorelaxation in this tissue. In addition, $N^{G}$-nitro-D-arginine methyl ester, known to lack inhibitory action on NO synthase, showed concentration-dependent potentiation of the photorelaxation. Oxygen radical generating system via copper＋ascorbic acid and guanylate cyclase inhibitor, methylene blue, significantly (p<0.05) inhibited the streptozotocin-potentiated photorelaxation. Nitrite was accumulated by photolysis of streptozotocin, $N^{G}$-nitro-L-arginine methyl ester and $N^{G}$-nitro-D-arginine methyl ester, in a concentration and exposure time dependent manner. These observations indicate that NO is a potent relaxant of rabbit and human corpus cavernosum and further support the hypothesis that NO is released by photolysis from NO- and N $O_2$-carrying molecules.lecules.

• 한국균학회지
• /
• 제36권2호
• /
• pp.183-188
• /
• 2008

3단계를 거처 식용 가능한 다발구멍장이버섯으로부터 분리한 혈전용해효소의 비활성은 30.49 U/mg이었으며, MALDI-TOF/MS로부터 분자량이 30086.41 Da이었다. 일차 아미노산 구조는 Glu-Thr-Val-Thr-Glu-Thr-Thr-Ala-Pro-Trp-Gly-Leu-Ser-Arg-Ile으로 밝혀졌으며, pH 8.0에서 pH 10.0의 넓은 범위에서 큰 활성을 나타내는 alkaline protease로, 최적온도는 $50^{\circ}C$이며, $30^{\circ}C$까지는 대체로 열에 안정한 효소였다. 이 효소는 합성 기질 N-Suc-Ala-Ala-Pro-Phe pNA을 강하게 분해하였으며, $Hg^{2+}$ 금속이온의 첨가로 효소 활성이 완전히 사라졌다. 효소저해제인 PMSF의 첨가로 혈전용해활성이 사라지는 결과로부터 serine 분해효소임을 알 수 있었다.

• Bulletin of the Korean Chemical Society
• /
• 제31권4호
• /
• pp.984-988
• /
• 2010

1-(Fluoren-2-yl)-benzo[d][1,2,3]triazoles 5a-b were synthesized starting from 2-nitrofluorene. 2-Nitrofluorenes 1a-b were reduced by catalytic hydrogenation, reacted with 2,4-dinitrofluorobenzene followed by catalytic hydrogenation to afford 2-(N-2,4-diaminophenyl)aminofluorenes 4a-b. Diazotization of 4a-b with $NaNO_2/H_2SO_4$ followed by treatment with $H_3PO_2$ gave 5a-b. Sulfonation of 5a-b yielded 7-benzotriazol-1-yl-fluorene-2-sulfonic acids 6a-b. The structures of 5b and 6b were firmly identified by X-ray crystal analysis in addition to $^1H$ NMR, $^{13}C$ NMR, and elemental analysis.

• Environmental Engineering Research
• /
• 제25권4호
• /
• pp.529-535
• /
• 2020

The present study investigated the photodegradation of synthetic organic dye; violet-3B, without and with the addition of C-N-codoped TiO₂ catalyst using a visible halogen-lamp as a light source. The catalyst was synthesized by using a peroxo sol-gel method with free-organic solvent. The effects of initial dye concentration, catalyst dosage, and pH solution on the photodegradation of violet-3B were examined. The efficiency of the photodegradation process for violet-3B dye was higher at neutral to less acidic pH. The kinetics reaction rate of photodegradation of violet-3B dye with the addition of C-N-codoped TiO₂ followed pseudo-first order kinetics represented by the Langmuir-Hinshelwood model, and increasing the initial concentration of dyes decreased rate constants of photodegradation. Photodegradation of 5 mg L^-1 violet-3B dye achieved 96% color removal within 240 min of irradiation in the presence of C-N-codoped TiO₂ catalyst, and approximately 44% TOC was removed as a result of the mineralization.

• 한국재료학회지
• /
• 제15권11호
• /
• pp.730-734
• /
• 2005

Cr-Al-Si-N coatings were deposited on WC-Co substrates by a hybrid coating system of arc ion plating and DC magnet :on sputtering technique in $N_2/Ar$ mixture. The Cr-tll-Si-N coatings were synthesized with different Si contents. Their microstructure and mechanical properties were systematically investigated. The average size of crystallites largely decreases with the increase of Si content compared with Cr-Al-N. The microhardness of Cr-Al-Si-N coatings largely increases from 24 to 55 GPa. The enhanced hardness is believed to originate from the microstructural change by the fine composite microstructure of Cr-Al-N coatings with Si addition. The average friction coefficient of Cr-Al-Si-N coatings decreases from 0.84 to 0.45 with increasing Si content up to $16\;at.\%$.

• The Korean Journal of Physiology and Pharmacology
• /
• 제13권3호
• /
• pp.139-145
• /
• 2009

The purpose of this study was to evaluate the effects of the water extract of Samultang (SMT), a Chinese herb, on apoptotic cell death by $H_2O_2$-induced oxidative stress in SK-N-M C cells. A nuclear fragmentation was observed via fluorescence imaging 12 h after exposure to 30 ${\mu}M$ $H_2O_2$ and DNA laddering was detected via agarose electrophoresis gel. In addition, increases in sub-G1 phase and cleavage of the PARP protein were observed. However, treatment with SMT for 2 h prior to $H_2O_2$ exposure significantly reduced apoptotic cell death induced by incubation with 30 ${\mu}M$ $H_2O_2$ in SK-N-MC cells. Pre-incubation with water extract of SMT for 2 h prevented the $H_2O_2$-induced decrease in mitochondrial transmembrane potential. SMT also attenuated the increase in caspase-3 activity and the breakdown of PARP protein caused by $H_2O_2$-induced oxidative stress. These results suggest that the water extract of SMT provides inhibition of apoptotic cell death against oxidative injury in SK-N-MC cells.

• Asian-Australasian Journal of Animal Sciences
• /
• 제20권11호
• /
• pp.1699-1704
• /
• 2007

This experiment was carried out to evaluate the effects of adding encapsulated-glucose, glucose, sorbic acid or prefermented juice of epiphytic lactic acid bacteria (FJLB) on the fermentation quality and residual mono- and disaccharide composition of Italian ryegrass (Lolium multiflorum Lam) silages. The additive treatments were as follows: (1) control (no addition), (2) encapsulated-glucose addition at 0.5% for glucose, (3) glucose addition at 1%, (4) sorbic acid addition at 0.1%, (5) FJLB addition at a theoretical application rate of $2.67{\times}10^5$ CFU (colony forming unit) $g^{-1}$, on a fresh weight basis of Italian ryegrass. Although control and encapsulated-glucose treatments had higher contents of butyric acid (33.45, 21.50 g $kg^{-1}$ DM) and ammonia-N/Total nitrogen (114.91, 87.01 g $kg^{-1}$) as compared with the other treated silages, the fermentation in all silages was clearly dominated by lactic acid. This was well indicated by the low pH (4.38-3.59), and high lactic acid/acetic acid (4.39-22.97) and lactic acid content (46.85-121.76 g $kg^{-1}$ DM). Encapsulated-0.5% glucose and glucose addition increased lactic acid/acetic acid, and significantly (p<0.05) decreased ammonia-N/total nitrogen, and the contents of butyric acid and total volatile fatty acids (VFAs) as compared with the control. However, there were higher butyric acid and lower residual mono-and di-saccharides on the two treatments as compared with sorbic acid and FJLB addition, and their utilization efficiency of water soluble carbohydrates (WSC) was lower than that of both sorbic acid and FJLB additions. Sorbic acid addition showed the lowest content of ethanol and ammonia-N/total nitrogen, and the highest content of residual fructose and total mono-and disaccharides as well as the higher lactic acid/acetic acid value. Sorbic acid addition decreased the loss of mono-and disaccharides, and inhibited the activity of clostridial and other undesirable bacteria, and greatly increased the utilization efficiency of fermentable substrates by epiphytic LAB. FJLB addition had the lowest pH value and the highest lactic acid content among all additive treatments, with the most intensive lactic acid fermentation occurring in FJLB treated silage. This resulted in the faster accumulation of lactic acid and faster pH reduction. Sorbic acid and FJLB addition depressed clostridia or other undesirable bacterial fermentation which decreased the WSC loss and saved the fermentable substrate for lactic acid fermentation.

• Asian-Australasian Journal of Animal Sciences
• /
• 제12권1호
• /
• pp.28-35
• /
• 1999

The effects of addition of celulases (A cremonium cellulolyticus and Trichoderma viride, CE), a commercial inoculum containing lactic acid bacteria (Lactobacillus casei, LAB), fermented green juice (macerated napier grass with water was incubated anaerobically with 2% glucose for 1 day, FGJ) and glucose (G), and regional difference of ensiling on napier grass (Pennisetum purpureum Schum.) silage were studied by using 900 ml laboratory glass bottle silos under 30 and $40^{\circ}C$ storage conditions in 1995 and 1996. Experiment 1 was carried out to compare the addition of CE, LAB, FGJ and the combinations. Silages were stored for 45 days after ensiling. Experiment 2 studied the effects of applications of CE, LAB, FGJ and G. Experiment 3 was carried out using the similar additives as experiment 2 except for LAB. Silages were stored for 60 days in the experiments 2 and 3. Experiments 1 and 2 were done in Nagoya, and experiment 3 in Okinawa. Sugar addition through CE or G improved the fermentation quality in all the experiments, which resulted in a greater decrease in the pH value and an increased level of lactic acid, while butyric acid contents increased under $30^{\circ}C$ storage condition in CE addition. LAB and FGJ additions hardly affected the silage fermentation quality without additional fermentable carbohydrate. But the combination of LAB, FGJ and glucidic addition (CE and G) improved the fermentation quality. The effect of the regional difference of ensiling between temperate (Nagoya; $35^{\circ}$ N) and subtropical (Okinawa; $26.5^{\circ}$ N) zones on silage fermentation quality was not shown in the present study.

• 대한전기학회:학술대회논문집
• /
• 대한전기학회 1999년도 하계학술대회 논문집 D
• /
• pp.1925-1927
• /
• 1999

At the study, it has fabricated Al/AlN/GaAs MIS capacitor using DC reactive sputtering method. To applicate GaAs semiconductor in a MIS devices, investigated capability of AIN thin film by the insulator layer. Also it has investigated inversion of C-V characteristics by addition of the hydrogen(hydrogen concentration: 5%) and it has investigated that leakage current has $10^{-8}A/cm^2$ for 1 MV/cm breakdown electric field of I-V characteristics.

• Journal of information and communication convergence engineering
• /
• 제3권3호
• /
• pp.163-166
• /
• 2005

The Key exchange protocols are very crucial tools to provide the secure communication in the broadband satellite access network. They should be required to satisfy various requirements such as security, Key confirmation, and Key freshness. In this paper, Two authenticated key exchange protocols TPEKE-E(Two Pass Encrypted Key Exchange-Exchange-Efficient) and TPEKE-S(Two Pass Encrypted Key xchange-Secure) are introduced. A basic idea of the protocols is that a password can be represented by modular addition N, and the number of possible modular addition N representing the password is $2^N$. The TPEKE-E is secure against the attacks including main-in-the-middle attack and off-line dictionary attack, and the performance is excellent so as beyond to comparison with other authenticated key exchange protocols. The TPEKE-S is a slight modification of the TPEKE-E. The TPEKE-S provides computational in feasibility for learning the password without having performed off line dictionary attack while preserving the performance of the TPEKE-E.