• 제목/요약/키워드: inhibition rate

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PEBAX/AP 열가소성 고체추진제의 연소 억제 방안 연구 (Study of the Inhibition on the Combustion of PEBAX/AP Thermoplastic Propellant)

  • 이형진;정해영;조준현;이영근;이호진
    • 한국추진공학회지
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    • 제17권5호
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    • pp.18-26
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    • 2013
  • AP 기반의 혼합형 열가소성 고체 추진제의 연소 억제 방안과 그 효과를 제시하였다. 입자 사이즈가 다른 AP를 적용한 효과와 0.5%~2.0%의 LiF가 미치는 영향을 분석하기 위해 PEBAX/AP 열가소성 고체 추진제에 대한 지상연소 시험을 통해 연소속도 및 압력 지수를 산출한 후 비교 분석하였다. 분석결과, 큰 AP 입자 사이즈를 적용하는 것과 2.0% 이내의 LiF 첨가는 연소속도를 감소시키는 효과를 보였으며 본 논문에서는 이에 대한 각각의 영향을 정량적으로 제시하였다.

향유와 꽃향유 향기성분의 생리활성 검정 (Biological Activity of Flavor Components Extracted from Elsholtzia ciliata and Elsholtzia splendens)

  • 정재훈;손현옥;신한재;현학철;이동욱;임흥빈
    • 한국연초학회지
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    • 제27권1호
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    • pp.19-30
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    • 2005
  • This study was to evaluate the biological activity of flavor components extracted from E. ciliata and E. splendens in order to survey the possibility applicable to tobacco and food industry. Flavor components were extracted with dividing into three parts; essential oil, absolute, oleoresin. In the nonenzymatic lipid peroxidation system, the inhibition rate($\%$) of essential oil were $67.3\;\pm\;20.7\%,\;58.1\;\pm\;19.3\%$ at the concentration of 50 ${\mu}g/mL$ of E. ciliata and E. splendens, respectively. The inhibition rate($\%$) of the oleoresin in E. ciliata was higher than one in E. splendens. In the enzymatic lipid peroxidation system, the inhibition rate($\%$) of essential oil and oleoresin was$14.28\;\pm\;2.38\%,\;and\;65.93\;\pm\;0.01\%,\;and\;was\;22.58\;\pm\;2.84\%\;and\;40.73\;pm\;6.04\%$. The oleoresin of two species were showed above $90\%$ of the inhibition rate($90\%$) against autooxidative lipid peroxidation system. $EC_{50}$ values in neutral red uptake assays 24 h of exposure times were $23.3\;{\mu}g/mL,\;341.0\;{\mu}g/mL\;and\;17.2\;{\mu}g/mL$ in essential oil, absolute and oleoresin from E. ciliata respectively, and were $46.4\;{\mu}g/mL,\;681.7\;{\mu}g/mL\;17.6\;{\mu}g/mL$ in three extractions of E. splendens. Oleoresin of two species showed high rate in the cytotoxic effect by neutral red uptake assay. Absolute and oleoresin did not show antibiotic and mutagenic activity. On the contrary, essential oil with over 500 ug/plate showed antibiotic and mutagenic activity in Ames test. Essential oil and oleoresin have a prolongating effect the ciliostasis of rat trachea. This results indicate that flavor components extracted from E. ciliata and E. splendens can be considered to be toxicological safe and to be the possibility applicable the cigarette, food and drug industry as a flavor for expectoration.

고정화균체 반응기에서 L-Sorbose 연속생산

  • 신혜원;신봉수;신철수
    • 한국미생물·생명공학회지
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    • 제25권1호
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    • pp.68-74
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    • 1997
  • The conversion of D-sorbitol to L-sorbose by Gluconobater suboxydans was analyzed, and continuous production of L-sorbose was carried out in immobilized cell reactors. L-Sorbose production by high densities of resting cells was more effective than by conventional batch fermentations. Sorbitol dehydrogenase, an enzyme converting D-sorbitol to L-sorbose, did not suffer from substrate inhibition, but from product inhibition. When L-sorbose production was carried out with Ca-alginate-immobilized cells, about 60 g/l of L-sorbose was obtained. On the other hand, when the corn steep liquor (CSL) concentration of medium was reduced to 0.08%, 80 g/l of L-sorbose was obtained. Outgrowth inside the immobilized carriers was thought to block the pores of the carriers so that substrate could not easily diffuse through the carriers. Continuous production of L-sorbose was well accomplished in a bubble column reactor, and 6. 5 g/l.h of productivity and 81.2% of yield were obtained at a substrate feeding rate of 0.08h$^{-1}$ under the optimum conditions with carrier volume of 55% and aeration rate of 3 vvm.

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활성슬러지 혼합미생물과 Nocardia asteroides에 의한 페놀화합물 분해시 양성자이온의 영향 (Proton Effect on the Degradation of Phenolic Compound by Activated Sludge and Nocardia asteroides)

  • 조관형;조영태;우달식
    • 한국환경과학회지
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    • 제11권6호
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    • pp.561-567
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    • 2002
  • This study was investigated to evaluate the effect of the sodium ion and pH on toxicity of dinitrophenol at high concentrations (0.41 to 0.54 mM), over a sodium concentration range of 0.1 mM to 107 mM and over a pH range of 5 to 9. The concentration of sodium ions in the activated sludge mixed liquor seemed to have very little effect on dinitrophenol toxicity. However, lack of sodium in the growth media resulted in a reduction of the dinitrophenol degradation rate by bacterial isolate from the activated sludge culture, which has been identified as Nocardia asteroides. Dinitrophenol inhibition was found to be strongly dependent on mixed liquor pH. The dinitrophenol degradation rate was highest in the pH range of 6.95 to 7.84; at pH 5.94 degradation of 75 mg/L dinitrophenol was significantly inhibited; at pH < 5.77, dinitrophenol degradation was completely inhibited after approximately 30% of the dinitrophenol was degraded.

주목류의 생물활성 연구 (A Study on the Boilogical Activity of Taxus spp.)

  • 김태희
    • 생약학회지
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    • 제21권2호
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    • pp.142-147
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    • 1990
  • Yew cortex, twigs and leaves(Florida yew, Taxus floridana Nutt et Champ; Pacific, yew Taxus brevifolia Nutt(Taxaceae)) were extracted with MeOH and $CHCI_3$, respectively, and then the chloroform extract was fractionated by silica column chromatography. As biologically active substances, taxol derivatives were identified and several biological activity tests were followed. The results showed that it bad no antimosquito activity and inhibited the growth of root meristem of cress seeds. The chloroform ext. of Florida yew showed 91%, inhibition rate at 400 ppm and the taxol fractions of Pacific yew did 91% at 200 ppm, 94% at 100 ppm. In the antitumor activity tests in vitro against a cultured cell line of L1210 mouse leukemia, Pacific yew showed 99% inhibition rate at 1.0 ppm and Florida yew did 97% at 10 ppm.

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배합약물(配合藥物)의 흡수(吸收)에 관(關)한 생물약제학적(生物藥劑學的) 연구(硏究) 1. Salicylamide에 항(抗) Histamine제(劑)를 배합(配合)하였을 때의 흡수효과에 관(關)하여 (A Biopharmaceutical Study on the Absorption of Some Compounding Drugs)

  • 김재완
    • Journal of Pharmaceutical Investigation
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    • 제1권1호
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    • pp.78-84
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    • 1971
  • The comparative studies were made on Salicylamide, used individually and compounded with antihistaminics as regards. (1) the absorption rate through isolated rat small intestine (in vitro) (2) the absorption rate through rat small intestine (in vivo), and the following effects were found. 1. The Absorption velosity of 2 m Mole gm. of salicylamide in the small intestine were decreased, when the agents compounded with tripelennamine indicating the greatest absorption inhibition in the case of m Mole gm. of tripelennamine. 2. The Absorption velosity of 2m Mole gm. of salicylamide in the small intestine were decreased, when the agents compounded with diphenhydramine indicating the greatest absorption inhibition in the case of 2m Mole gm. of diphenhydramine. 3. The Absorption velosity of 2m Mole gm. of salicylamide in the small intestine were increased, when the agents compounded with chlorpheniramine indicating the greatest absorption augmentation in the case of 0.2m Mole gm. of chlorpheniramine.

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Inhibition of Purine Nucleoside Phosphorylase (PNP) in Micrococcus luteus by Phenylglyoxal

  • Choi, Hye-Seon
    • Journal of Microbiology
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    • 제34권3호
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    • pp.270-273
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    • 1996
  • Micrococcus luteus purine nucleoside phosphorylase (PNP) has been purified and characterized. The physical and kinetic properties have been described previously. Chemical modification of the enzyme was attempted to gain insight on the active site. The enzyme was inactivated in a time-dependent manner by the arginine- specific modifying reagent phenylglyoxal. There was a linear relationship between the observed rate of inactivation and the phenylglyoxal concentration. At 30 $^{\circ}C$ the bimolecular rate constant for the modification was 0.015 $min^{-1}mM^{-1}$ in 50 mM $NaHCO_3$ buffer, pH 7.5. The plot of logk versus log phenylglyoxal concentration was a strainght line with a slope value of 0.9, indicating that modification of one arginine residue was needed to inactivate the enzyme. Preincubation with saturated solutions of substrates protected the enzyme from inhibition of phenylglyoxal, indicating that reactions with phenylglyoxal were directed at arginyl residues essential for the catalytic functioning of the enzyme.

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모잘록병의 생물학적 방제를 위한 유효 미생물 선발방법 및 효과 (Screening and effect of antagonists for biological control of plant pathogen)

  • 이백석;최성원;최기현;이재호;김은기
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2002년도 생물공학의 동향 (X)
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    • pp.386-389
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    • 2002
  • 식물의 토양전염병을 유발하는 P. aphanidermatum 및 R. solani에 대한 길항력, 생장속도 및 표면장력 감소를 고려한 RPI (relative performance indices) 기법을 이용하여 90 여개 후보균 중 #16 길항균을 선정하였다. 선정된 Bacillus sp. #16은 16S rRNA 서열을 분석한 후 GenBank에서 비교한 결과 B. subtilis DSM10과 99% 유사성을 보였다. 또한 pot test 결과 오이 모잘록병에 대해 우수한 방제가를 보였다.

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쥐에서 비스테로이드성 항염증제의 투여후 항염효과와 혈청 및 조직내 구리함량변화에 관한 연구 (Studies on the Antiinflammatory Effects and the Change of Copper Content after Administration of Nonsteroidal Antiinflammatory Drugs in Rats)

  • 허인회;임철빈
    • 약학회지
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    • 제26권2호
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    • pp.97-103
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    • 1982
  • This paper presents anti-inflammatory effects of nonsteroidal anti-inflammatory drugs and their copper complexes, and the change of content of copper in serum, liver, brain and edema foot induced by 1% carrageenan in rats, and also investigation of stomach hemorrhage. The results were as follows. 1. The content of copper decreased in liver and brain, however, the concentration of copper significantly increased in serum and edema site after carrageenan injection in rats. 2. The content of copper in serum and edema site was decreased after administration of anti-inflammatory drugs. 3. Edema inhibition rate of aspirin was, higher than that of copper (II) aspirinate, but edema inhibition rate of copper complex of naproxen was markedly higher than that of naproxen. 4. Hemorrhage of stomach of copper salicylate was higher than that of sodium salicylate, but hemorrhage of stomach of sodium naproxen was higher than that of copper naproxen.

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홍경천(紅景天)(Rhodiola rosea Root)의 항암(抗癌)효과에 대한 연구(硏究) (A Study on the Effects of Rhodiola rosea Root on the Cancers)

  • 김정열;성낙술;이영종
    • 대한본초학회지
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    • 제21권1호
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    • pp.79-87
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    • 2006
  • Objectives : Effects of Rhodiola rosea root on cancers on stomach, breast, lung, and liver were examined. Methods : Water extracts and methanol extracts of Rhodiola rosea root were treated on cancer cells, and its effects on cancers were examined. Results : 1. Water extracts and methanol extracts of Rhodiola rosea root was less harmful in its lowest density 0.25 mg/mL (9.l%와 10.5%), but became more harmful as its density increased. 2. As for human stomach adenocarcinoma cells AGS, breast adenocarcinoma cells MCF-7, and lung carcinoma cells A549, methanol extracts showed 70-77% inhibition of cancer cells in high density(1 mg/mL), and water extracts showed 60-70% inhibition rate and its selective death rate was less than 2.5. Conclusion : Rhodiola rosea root can be used to treat cancers and to increase immunity.

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