• Journal of Energy Engineering
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• v.2 no.1
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• pp.54-67
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• 1993

Two turbulent reaction models of the premixed CC1$_4$/CH$_4$/air mixture are successfully incorporated in a 3-dimensional computer program and is applied for Dow Chemical incinerator equipped with two main off-center burners. The first reaction model is fast chemistry model(model 1), in which chemical reaction is governed by the turbulent mixing itself. And the second one is nonequilibrium model(model 2), where the effect of the chemical kinetics due to the presence of CC1$_4$is considered by the incorporation of the burning velocity data of CC1$_4$. The second model not only shows the flame inhibition trend due to the presence CC1$_4$compound, but also predicts qualitatively the vortical stratification of the CC1$_4$concentration appeared experimentally at the kiln exit. Other comparisions of two models are made in detail.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1992.05a
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• pp.51-51
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• 1992

신의 약품을 개발하는 과정에서 안전성의 평가는 신약후보물질의 인체에 대한 유해의 정도를 파악하고 신약후보물질들의 독성을 초기에 검색하여 의약품으로써의 개발여부를 결정하는데 기여함으로써 개발연구에 소요되는 시간 및 경제적 낭비를 줄일 수 있는 매우 중요하고도 필수적인 단계이다. 또한 생체독성억제물질의 개발에 관한 연구는 다양한 연구기법을 활용하여 각종 생체이물에 의한 생체독성의 발현을 억제하거나 발현된 독성반응을 완화, 경감시키는 물질이나 기법을 탐색함으로써 신약후보물질의 창출에 기여 할 수 있을 것으로 기대되고 있다. 이와 같은 관점에서 안전성 연구팀은 그 연구분야를 크게 특수독성검색기술 개발연구와 생체독성억제물질 개발연구 분야로 대별하고 1)발암조기검색법 개발연구 2)독성물질 대사효소계에 관한 연구 3)유전자 손상억제물질개발연구 4)간독성 억제물질 개발연구 5)신장독성 억제물질 개발연구 6)면역독성 억제물질 개발연구 7)대사 및 내분비계 독성억제물질 개발연구 8)순환기계독성 억제물질 개발연구 등 총 8개의 세부과제와 안전성평가제도의 국제화를 위한 제도 및 기준에 관한 연구를 수행하고 있는바 이들의 연구목표와 내용 그리고 1차년도의 연구결과를 개괄적으로 소개함으로써 본 과제가 포괄하는 제반 안전성연구내용에 대한 이해를 도모하고자 한다.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.37 no.1
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• pp.67-73
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• 2011

Dental bacteria can cause gum diseases, i.e. gingivitis and periodontitis, by inducing inflammation in human gingiva. Therefore, the most effective way to prevent and treat gum diseases is the control of the inflammatory reactions induced by dental bacteria. Almost all present dental care products contain anti-bacterial agents to eliminate dental bacteria. However, recent studies report that even heat-killed dental bacteria can induce the inflammation responses in oral cells. Therefore, the method using anti-bacterial agents should be improved for better anti-inflammatory effect and the effective natural anti-inflammatory substances need to be found. In addition, the mechanisms of gingival inflammation should be elucidated. In this study, we tried to find out the mechanism of the gingival inflammation and effective natural anti-inflammatory substances with human gingival epithelial cells and Prevotella intermedia which is well known as a typical dental bacteria inducing gingivitis and periodontitis. In results, Prevotell intermedia initiated the gingival inflammation response by stimulating gingival epithelial cells to release an inflammatory cytokine, IL-8. Furthermore, the inflammation by Prevotella intermedia is related to COX-2, AP-1, and TNF-${\alpha}$ pathways. Green tea extract could effectively suppress the inflammatory responses induced by Prevotella intermedia. We find out the effective natural substance for the improvement of gum diseases by studying the mechanism of the gingival inflammation induced by dental bacteria.

• Journal of Preventive Medicine and Public Health
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• v.28 no.1 s.49
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• pp.27-42
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• 1995

The in vivo and in vitro humoral and cell-mediated immune responses of lymphocytes of BALB/c mouse exposed to mercury chloride$(HgCl_2)$ were investigated. In vitro exposure of the splenocytes to mercury chloride produced overt cytotoxicity in 3 hours period. The $IC_{50}$(the concentration required to inhibit a splenocyte viability by 50%) for mercury chloride was >0.1mM for cytotoxicity. In vivo mercury chloride exposed mice were significantly depressed delayed type hypersensitivity(DTH) response to sheep red blood cells(SRBC) in a dose-dependent manner compared with control group. Mercury chloride inhibited the proliferative responses of splenocytes to lipopolysaccharide, pokeweed mitogen, concanavalin A and phytohemagglutinin in a dose-dependent manner. Hemagglutinin response to SRBC in mercury chloride exposed mice was significantly depressed in a dose-dependent manner compared with control group. After 7 weeks of mercury chloride exposure in vivo, mercury chloride induced an increase of nonspecific serum $IgG_1$ and IgE levels in BALB/c mice.

• Journal of the Korean Society of Food Science and Nutrition
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• v.14 no.3
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• pp.253-258
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• 1985

It was aimed to elucidate the underlying mechanism which is elevated the systemic arterial blood pressure by cadmium(Cd). By using the isolated vas deferens and tail artery from Cd-poisoned rats, it was undertaken to see whether the ${\alpha}-adrenoceptor$ activity and prostaglandins action on the twitch response to electrical stimulation were altered. It was discussed in relation with sympathetic nerve activity. The response to electrical stimulation in vas deferens from Cd-poisoned rats was much enhanced, and frequency 50(Freq.50) was significantly lowered, comparing to control. However, the response of rat tail artery was attenuated by Cd. Inhibitory action of clonidine on the twitch response of vas deferens to electrical stimulation was decreased by Cd-poisoning. However, the increase in response in the presence of methoxamine was not affected. The inhibitory action of prostaglandin $E_2$ on the twitch response in the vas deferens but not in the tail artery was abolished or rather inverted by Cd-poisoning. In the tail artery from Cd-poisoned rats, the maximum contraction to methoxamine or clonidine was significantly decreased, however, $ED_{50}$ of both agonists was not changed. These results suggest that in vas deferens the autoreceptor of presynaptic membrane is inhibited by Cd-poisoning, by which mechanism the sympathetic activity is being enhanced and this alteration may be causally related to the elevation of arterial pressure.

• Korean Journal of Food Science and Technology
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• v.42 no.4
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• pp.488-493
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• 2010

We investigated the effect of Perilla frutescens (PF) ethanol extract powder (PF-E30) on the local allergic reaction activated by anti-DNP IgE and the mast cell-mediated immediate-type allergic reactions induced by compound 48/80 in a mouse model. One gram of PF powder extracted with 30% ethanol at $80^{\circ}C$ contained 12.3 mg of rosmarinic acid. Oral administration of PF-E30 (0.1 to 0.5 mg/kg body weight) significantly reduced plasma histamine levels and inhibited histamine release from peritoneal mast cells in mice activated by compound 48/80 or anti-DNP IgE. Moreover PF-E30 dose-dependently inhibited the production of antigen-induced IgE. These results indicate that the PF ethanol extract inhibits mast cell-mediated immediate-type allergic reactions in vivo and in vitro.

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.230-236
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• 1996

Pot experiment in greenhouse was conducted to determine the effect of growth and anatomical characteristics of bensulfuron on the seedlings of rice and barnyardgrass. Formulated bensulfuron was soil applied at 102g ai/ha to rice and barnyardgrass grown under various cropping patterns at 5 days after seeding or transplanting. At 10 days after application, plants were harvested to examine growth and anatomical changes of rice and barnyardgrass. Bensulfuron did not affect the growth and development of rites under dry seeded condition and trnsplanting condition while inhibited severely those of rice under water-seeded condition compared with untreated control. Under water-seeded condition, root growth of rice was much more severely inhibited by bensulfuron than shoot growth. The herbicide retarded the growth of barnyardgrass under dry-seeded condition and more severely inhibited than that under water-seeded condition. Microscopically, the anatomical change induced by bensulfuron occurred only in barnyardgrass under dry-seeded condition, and involved constriction of leaf primordia within leaf sheaths, rupture of mesophyll cell, and irregular cell arrangement. These anatomical alterations differed from and were not associated with the differential growth response.

• Applied Biological Chemistry
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• v.35 no.2
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• pp.82-86
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• 1992

This research was carried out to investigate antimutagent effect of peach enzymatic browning reaction products(PEBRP) obtained by reacting each of polyphenol compounds with oxidase extracted from Korea-cultivated peach. In methods, rec-assay with B. subtilis strains $H17(rec^+)\;and\;M45(rec^-)$, and Ames test with S. typhimurium TA98 and TA100 were used. The spore rec-assay of PEBRP, pyrogallol, hydroxyhydroquinone, homocatechol and caffeic acid were not showed mutagenicity. In the effects of various metal ions$(Al^{3+},\;Cu^{2+},\;Fe^{2+},\;Mn^{2+},\;Ni^{2+},\;Pb^{2+},\;Zn^{2+})$ on the rec-assay, all PEBRP except caffeic acid was increased inhibition zone(5 mm) only with $Zn^{2+}$. In paticular, the Py-PEBRP was decreased the difference of inhibition zone of growth on MMC(mitomycin C). In results of Ames test, all PEBRP were not showed mutagenicity on S. typhimurium TA98 and TA100; however, Ca-PEBRP and Hca-PEBRP were suppressed mutagenic effects on Trp-P-1 and B(a)P in the presence of S-9Mix.

• The Korean Journal of Pharmacology
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• v.23 no.1
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• pp.33-44
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• 1987

NADPH oxidase dependent superoxide generation and phagocytosis in neutrophils stimulated with opsonized zymosan or heat aggregated IgG were coincided with the process of calcium uptake. The responses in activated neutrophils were enhanced with increasing concentrations of extracellular calcium and these effects were significantly inhibited by calcium chelators, EGTA and EDTA. The superoxide generation in activated neutrophils was reduced by dantrolene and chlorpromazine. Calcium antagonists, bepredil, diltiazem, verapamil, nifedipine and nimodipine effectively inhibited the calcium uptake, superoxide generation and phagocytosis in activated neutrophils, and NADPH oxidase activity was also inhibited. The results suggest that calcium antagonists may inhibit the superoxide generation and phagocytosis in activted neurtophils by the inhibition of calcium influx and by the action on intracellular redistribution of calcium and NADPH oxidase system.

• Journal of Acupuncture Research
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• v.19 no.6
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• pp.155-170
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• 2002

면역억제와 면역항진의 작용을 지닌 녹용(鹿茸)약침의 실험쥐에서의 type II collagen(CII)으로 유발된 관절염(CIA)에 대한 효과를 연구하였다. 본 실험에서 녹용(鹿茸)약침군과 생리식염수군을 대조군으로 하여 실험쥐에게 약침시술을 하였다. 녹용(鹿茸)약침이 CII에 작용하는 세포반응에 대한 효과를 검정하였는데, 대조군에서는 CII 유발주사 후 24일에 관절염이 관찰되었고, CIA의 정도가 점차적으로 심해졌다. 생리식염수 처리군과 비교해 24일 동안 하루에 한번 $50{\mu}g/kg$ 이상 용량의 녹용(鹿茸)약침은 CII 처리 T cell의 interleukin 2(IL-2)와 interferon-${\gamma}$($IFN-{\gamma}$) 생산능력을 억제했다. 또한 녹용(鹿茸)약침은 CII처리 임파절과 대식세포의 tumor necrosis facter ${\alpha}$($TNF-{\alpha}$)의 생산을 억제했다. 한편 CIA에 대한 약침효능의 지표는 녹용(鹿茸)약침을 14일간 하루에 한번씩 처리하면서, 소의 CII로 3주 간격으로 2번 유발접종을 실시하여 검정하였다. 첫 CII 유발접종과 동시에 일일 투여량 $100{\mu}g/kg$으로 14일간의 녹용(鹿茸)약침이 항체형성과 CII에 대한 지연형 과민성 뿐만 아니라 관절염의 증가도 막아주었다. 녹용(鹿茸)약침을 관절염 유발성 CII의 2차 접종과 동시에 시술한 결과, 관절염과 CII에 대한 면역반응을 억제하였다. 이에 저자는 CII로 유발된 관절염에 대한 녹용(鹿茸)약침의 억제효과에 대하여 보고하는 바이다.