• 제목/요약/키워드: concentration effects

검색결과 14,600건 처리시간 0.043초

마황(麻黃) 추출물이 항산화에 미치는 영향 (Effects of Ephedras Herba on the activity of antioxidant)

  • 송성민;임형호;권기록;임태진;송윤경
    • 대한약침학회지
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    • 제10권2호통권23호
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    • pp.57-65
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    • 2007
  • Objectives : The purpose of this study was to investigate the antioxidative effects of Ephedrae Herba extract. Methods : Total antioxidant status was examined by total antioxidant capacity(TAC), total antioxidant response(TAR) against potent free radical reactions, total phenolic content, DPPH radical scavenging activities, and the inhibitory effect of the extract on lipid peroxidation in rat liver mitochondria. Results : 1. TAC and TAR of Ephedrae Herba extract at the concentration of 5mg/ml were 3.76 and 1.65 mM Trolox equivalents , respectively. 2. Total phenolic content of Ephedrae Herba extract at the concenuation of 5mg/ml was 3.52 mM gallic acid equivalent. 3. Concentration of Ephedrae Herba extract at which DPPH radical scavenging activity was inhibited by 50% was 0.46mg/ml as compared to 100% by pyrogallol solution as a reference. 4. Ephedrae Herba extract at the concentration of 2mg/ml significantly decreased TBARS concentration by 97%, showing that Ephedrae Herba extract prevented lipid peroxidation at the low concentration. Conclusion : Thus antioxidant effects of Ephedrae Herba extract appear to be due to, at least in part, the prevention from free radicalsinduced oxidation, followed by inhibition of lipid peroxidation.

La 농도가 PLT 박막의 전기적 및 광학적 특성에 미치는 효과 (The effects of la content on the electrical and optical properties of (Pb, La)TiO$_{3}$ thin films)

  • 강성준;류성선;윤영섭
    • 전자공학회논문지A
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    • 제33A권2호
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    • pp.87-95
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    • 1996
  • We have studied the effects of La concentration on the optical and electrical properties of lead lanthanum titanate (PLT) thin films by using sol-gel method. Both the optical and electrical properties are greatly affected by the La concentration. The refreactiv eindices of the films varied from 2.23 to 1.93 with varying La concentration in the range from 15 to 33 mol%. The dielectric constants of the films vary form 340 to 870 with varying La concentration in the range form 15 to 33 mol%. Hysteresis loop becomes slimmer with the increase of La concentration form 15 to 28mol% and little fatter again with the increase of La concentration form 28 to 33 mol%. Among the films investigated in this research, PLT(28) thin film shows the best dielectric properties for the application to the dielectrics of ULSI DRAM's. At the frequency of 100Hz, the dielectric constant and the loss tangent of PLT(28) thin films are 940 and 0.08 respectively. Its leakage current density at 1.5${\times}10^{5}$V/cm is 1${\times}10^{-6}A/cm^{2}$. The comparision between the simulated and the experimental curves for the switching transient characteristics shows that PLT (28) thin films behaves like normal dielectrics.

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Cook-Chill System을 위한 생산품의 냉장저장 중 녹차 추출물의 첨가에 따른 일부 식중독균의 증식저해효과 (Inhibitory effect of partial Pathogen growth in virtue of Green Tea Extracts in Cold Storage Conditions of Products for Cook-Chill System)

  • 김혜영;정성미
    • 한국식품조리과학회지
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    • 제21권1호
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    • pp.47-52
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    • 2005
  • This study aimed to determine inhibitory effect of pathogen growth by adding green tea extracts to some cook-chill foods. For this study, chicken meat salad and pyeonyuk were blended with green tea extracts to different concentrations of 0, 2 and $3\%$ and prepared in a cook-chill system. S. typhimurium in chickien meat salad; Better antibacterial effects of green tea extracts were observed at a $3\%$ concentration, compared with a $2\%$ concentration. Populations of S. aureus in chicken meat salad; antibacterial effects at a $3\%$ concentration became significant from 3days while that at a $2\%$ concentration remained steady throughout the five-day duration. All three testing samples exhibited a decrease in populations of S. aureus during storage. In pyeonyuk, S. aureus counts at a $3\%$ concentration were 7.26 CFU/g on day 3 and declined to 6.61 CFU/g and 6.48 CFU/g on the following days, showing a greater degree of decline than that of a $2\%$ concentration.

난류 파이프 유동 내 물질전달에 대한 레이놀즈 수 영향: Part II. 순간농도장, 고차 난류통계치 및 물질전달수지 (REYNOLDS NUMBER EFFECTS ON MASS TRANSFER IN TURBULENT PIPE FLOW: PART II. INSTANTANEOUS CONCENTRATION FIELD, HIGHER-ORDER STATISTICS AND MASS TRANSFER BUDGETS)

  • 강창우;양경수
    • 한국전산유체공학회지
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    • 제17권3호
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    • pp.59-67
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    • 2012
  • Large Eddy Simulation(LES) of turbulent mass transfer in fully developed turbulent pipe flow has been performed to study the effect of Reynolds number on the concentration fields at $Re_{\tau}=180$, 395, 590 based on friction velocity and pipe radius. Dynamic subgrid-scale models for the turbulent subgrid-scale stresses and mass fluxes were employed to close the governing equations. Fully developed turbulent pipe flows with constant mass flux imposed at the wall are studied for Sc=0.71. The mean concentration profiles and turbulent intensities obtained from the present LES are in good agreement with the previous numerical and experimental results currently available. The effects of Reynolds number on the turbulent mass transfer are identified in the higher-order statistics(Skewness and Flatness factor) and instantaneous concentration fields. The budgets of turbulent mass fluxes and concentration variance were computed and analyzed to elucidate the effect of Reynolds number on turbulent mass transfer. Furthermore, to understand the correlation between near-wall turbulence structure and concentration fluctuation, we present an octant analysis in the vicinity of the pipe wall.

Utachlor가 귀리 (Avena sativa L.)의 세포분열 및 신장에 미치는 영향 (Effects of Butachlor on Cell Division and Cell Enlargement in Oat (Avena sativa L.))

  • 김재철
    • Journal of Plant Biology
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    • 제29권3호
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    • pp.167-173
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    • 1986
  • The effects of varying concentrations and durations of butachlor [N-(bytoxymethyl)-2-chlor-2', 6';-diethylacetanilide] treatment on oat (Avena sativa L.) root cell division were studied. Oats were treated from 0 to 48h with concentration ranging from 1$\times$10-6M to 1$\times$10-3M of butachlor. The highest concentration (1$\times$10-3M) of butachlor caused significant inhibition of cell division after 6h treatment. After 18h treatment, 49% and 66% inhibition of cell division occurred at 1$\times$10-5M and 1$\times$10-4M, respectively, while 16% inhibition of cell division occurred at 1$\times$10-6M concentration at same exposure period. Oat treated with 1$\times$10-5M and 1$\times$10-6M showed 69% and 38% inhibition of cell division after 36h. Increasing herbicide concentration at a specific time increased inhibition of cell division, and increasing the duration of treatment at a specific concentration also increased inhibition of cell division. In most instances the greatest inhibition of cell division occurred between 0 to 18h during 48h treatment. A range of concentration of 1$\times$10-5M to 1$\times$10-3M reduced cell enlargement significantly during 24h incubation period. The 1$\times$10-5M and 1$\times$10-3M caused 34% and 75% inhibition of cell enlargement. It was concluded that butachlor caused the growth inhibition of oats by inhibiting both cell division and cell enlargement.

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세신고가 알레르기성 비염에 미치는 효과 (The anti-allergic effect of SESHINGO(SSG))

  • 김민애;김미보;고우신;윤화정
    • 한방안이비인후피부과학회지
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    • 제21권3호
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    • pp.69-81
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    • 2008
  • Objective : The purpose of this study was find out the anti-allergic effects of SESHINGO on the allergic rhinitis. Methods : Cell viability was evaluated by the MTT assay. Cells were treated with the indicated concentration of SSG. $TNF-\alpha$ concentration was measured from cell supernatants using ELISA method. IL-4 concentration was measured from cell supernatants using ELISA method.$IFN-\gamma$ concentration was measured from cell supernatants using ELISA method. Total RNA was isolated, $TNF-\alpha$ and IL-4 mRNA expression was detected by RT-PCR analysis Total RNA was isolated, COX-1, COX-2 mRNA was analyzed by RT-PCR analysis. Results : 1. $\beta$-hexosaminidase release in RBL-2H3 cells were decresed by SESHINGO attentively. 2. Secreting ration of $TNF-\alpha$was restrained in RBL-2H3 cells by SESHINGO attentively. 3. Secreting ration of IL-4 was restrained in RBL-2H3 cells by SESHINGO attentively 4. Revelation of $TNF-\alpha$ mRNA was decresed in RBL-2H3 cells as concetration. 5. Revelation of.IL-4 mRNA was decresed in RBL-2H3 cells as concetration. 6. Revelation of COX-2 mRNA was decresed in RBL-2H3 cells. Conclusion : According to above results, to evaluate the effect of SSG on the anti-allergic effects.

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A comparison of 0.075% and 0.15% of ropivacaine with fentanyl for postoperative patient controlled epidural analgesia after laparoscopic gynecologic surgery

  • Jung, Hyun Chul;Seo, Hyo Jung;Lee, Deok Hee;Park, Sang-Jin
    • Journal of Yeungnam Medical Science
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    • 제34권1호
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    • pp.37-42
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    • 2017
  • Background: A motor blockade of lower limbs interferes with early ambulation and limits the usefulness of patient-controlled epidural analgesia (PCEA). The concentration of local anesthetic solution is a major determinant for motor block with PCEA. We compared the effects of epidural infusion of 0.075% ropivacaine with 0.15% epidural ropivacaine on postoperative analgesia, motor block of lower limbs, and other side effects. Methods: A total of 70 patients undergoing laparoscopic gynecologic surgery received epidural infusions (group R1, 0.15% ropivacaine with fentanyl; group R2, 0.075% ropivacaine with fentanyl). Pain score, motor block, and side effects (hypotension, nausea, vomiting, pruritus, urinary retention, dizziness, and numbness) were measured. Results: There were no significant differences in the demographic profiles between the groups. Pain scores of the group R1 and the group R2 were not significantly different. Motor block was more frequent in the group R1 (0.15% ropivacaine with fentanyl) than in the group R2 (0.075% ropivacaine with fentanyl). Conclusion: Lower concentration of ropivacaine (0.075%), when compared with higher concentration of ropivacaine (0.15%), seemed to provide similar analgesia with less motor blockade of the lower limbs for the purpose of PCEA.

Pediastrum duplex의 single cell 형성에 미치는 영양염류 및 무기탄소의 영향 (Effects of nutrient and inorganic carbon on single cell formation of Pediastrum duplex)

  • 조재형;노경호;박규현;장중석;남귀숙;황선진
    • 상하수도학회지
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    • 제32권2호
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    • pp.153-158
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    • 2018
  • In this study, effects of nutrient and inorganic carbon on single cell emergence during the cultivation of microalgae were observed using colonial green algae, Pediastrum duplex. The concentration of inorganic carbon had significant effect on single cell emergence and its growth, but nitrogen and phosphorus concentration showed minor effects. According to P. duplex cultivation experiment, single cell started to be emerged around 500~750 mg-C/L of inorganic carbon concentration and it was bloomed dramatically at the higher values. And growth of P. duplex was started to be surpressed at the single cell formation concentration. From the results, it could be said that when we operate the microalgae systems for cultivation/harvesting or wastewater treatment, in order to avoid single cell formation, inorganic carbon should be maintained to the proper level.

Effects of Glipizide on the Pharmacokinetics of Carvedilol after Oral and Intravenous Administration in Rats

  • Lee, Chong-Ki;Choi, Jun-Shik
    • Biomolecules & Therapeutics
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    • 제19권2호
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    • pp.237-242
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    • 2011
  • This study was designed to investigate the effects of glipizide on the pharmacokinetics of carvedilol after oral or intravenous administration of carvedilol in rats. Clinically carvedilol and glipizide can be prescribed for treatment of cardiovascular diseases as the complications of diabetes, and then, Carvedilol and glipizide are all substrates of CYP2C9 enzymes. Carvedilol was administered orally or intravenously without or with oral administration of glipizide to rats. The effects of glipizide on cytochrome P450(CYP) 2C9 activity and P-gp activity were also evaluated. Glipizide inhibited CYP2C9 activity in a concentration-dependent manner with 50% inhibition concentration ($IC_{50}$) of 18 ${\mu}M$. Compared with the control group, the area under the plasma concentration-time curve (AUC) was significantly increased by 33.0%, and the peak concentration ($C_{max}$) was significantly increased by 50.0% in the presence of glipizide after oral administration of carvedilol. Consequently, the relative bioavailability (R.B.) of carvedilol was increased by 1.13- to 1.33-fold and the absolute bioavailability (A.B.) of carvedilol in the presence of glipizide was increased by 36.8%. After intravenous administration, compared to the control, glipizide could not significantly change the pharmacokinetic parameters of carvedilol. Therefore, the enhanced oral bioavailability of carvedilol may mainly result from inhibition of CYP2C9-mediated metabolism rather than both P-gp-mediated effl ux in the intestinal or in the liver and renal elimination of carvedilol by glipizide.

Antibacterial Activity of Water Soluble Components of Elfvingia applanata Alone and in Combinations with Quinolones

  • Kim, Young-So;Eo, Seong-Kug;Oh, Ki-Wan;Lee, Chong-Kil;Lee, Young-Nam;Han, Seong-Sun
    • Mycobiology
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    • 제29권1호
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    • pp.11-14
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    • 2001
  • A preparation of water soluble components(EA) was made from carpophores of Elfvingia applanata(Pers.) Karst and its in vitro antibacterial activity on a number of bacterial species was examined by macrobroth dilution assay. Among 16 species of bacteria tested, the most potent antibacterial activity was observed against Staphylococcus epiderrnidis and Proteus vulgaris, of which MICs were 1.25 mg/ml. To investigate the antibacterial effects in combinations of EA with quinolone antibiotics, such as ciprofloxacin, enoxacin, lomefloxacin, norfloxacin, and ofloxacin, the fractional inhibitory concentrations(FICs) and the fractional inhibitory concentration indices(FICIs) for four bacterial strains were determined by macrobroth dilution checkerboard assay. Combinations of EA and quinolones exhibited either additive or indifferent effects of antibacterial activity in most instances. However, both synergistic and antagonistic effects were not observed in any cases.

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