• 제목/요약/키워드: Pure sciences

검색결과 782건 처리시간 0.028초

이팝나무 잎으로부터 항산화 및 항갈변물질의 분리 (Isolation of Antioxidant and Antibrowning Substance from Chionanthus retusa Leaves)

  • 이영남;정창호;심기환
    • 한국식품영양과학회지
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    • 제33권9호
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    • pp.1419-1425
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    • 2004
  • 본 연구는 이팝나무 잎의 용매분획물을 이용하여 DPPH 소거 작용, 환원력과 같은 항산화 활성과 tyrosinase 저해 활성을 실험한 결과 에틸 아세테이트 분획물에서 높은 항산화 및 tyrosinase 저해 활성을 나타내었다. 따라서 silica gel column chromatography와 MPLC를 이용하여 그 활성물질을 분리하였으며, 분리한 화합물은 $^1H$, $^{13}C$-NMR 및 2DNMR을 이용하여 luteolin-4'-O-glucoside로 구조동정을 하였다. 분리한 luteolin-4'-O-glucoside와 기존 항산화제와의 비교실험에서 DPPH 라디칼 소거 활성과 환원력은 시료의 농도가 증가함에 따라 활성이 증가하였다. 순수하게 분리한 luteolin-4'-O-glucoside를 이용하여 tyrosinase 저해 활성도 농도 의존적이었으며, $IC_{50}$ 값은 23.2 ${\mu}g/mL$로 나타났다. 그러므로 luteolin-4'-O-glucoside는 식품첨가물로 항산화제로서의 활용도 및 미백효과를 지니는 기능성 화장품원료로서 이용가치가 높을 것으로 생각된다.

외생균근(外生菌根)이 수분결핍(水分缺乏)된 루브라 오리나무 묘목(苗木)의 생리활동(生理活動)에 미치는 영향(影響) (Ectomycorrhizal Effect on Physiological Activities of Water-Stressed Nodulated Alnus rubra Seedlings)

  • 구창덕
    • 한국산림과학회지
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    • 제89권4호
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    • pp.513-521
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    • 2000
  • 루브라 오리나무 (Alnus rubra Bong.) 묘목에 질소고정균, Frankia를 접종하고, 이 묘목의 반을 외생균근균, Alplva diplophloeus 포자로 접종하여 인공생장상에서 16주 동안 길렀다. 그 결과, 외생균근 형성묘는 비균근묘보다 직경생장, 칠고정뿌리혹 형성 그리고 지상부 생체량에서 6~16% 더 켰다. 이들 묘목에 대하여 30시간 동안 수분결핍 처리를 하여 균근이 루브라 오리나무의 수분생리에 미치는 영향을 조사하였다. 이 수분 결핍동안 균근은 잎의 수분 포텐셜, 광합성, 그리고 질소고정활동에 영향을 미치지 않았다. 이 결과는 외생균근균 A. diplophloeus는 수분이 부족하지 않은 경우에는 루브라오리나무 묘목의 생장을 촉진시키지만 수분결핍 상태에서는 생리활동에 영향을 미치지 않음을 나타낸다.

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직독식 방출분광기를 이용한 지르콘사 중의 $SiO_2$$ZrO_2$의 분석 (Determination of $SiO_2$ and $ZrO_2$ in Zircon Sand by Optical Emission Spectrometer)

  • 김영만;정찬이;한봉한;최범석
    • 분석과학
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    • 제6권3호
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    • pp.275-282
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    • 1993
  • 지르콘사 광물에서 지르코니아를 회수하기 위하여 지르콘사를 분해 반응시킨 소성산물 중의 $SiO_2$$ZrO_2$를 DC arc source를 이용한 직독식 분광기로 동시 분석하였다. 순수한 금속산화물을 혼합하여 합성표준시료를 만들고 완충제(흑연)와 융제($Li_2B_4O_7$)의 혼합비를 조절하면서 최적의 들뜸조건을 선정하였다. 완충제와 흑연의 비를 0.22:1로 하고 시료와의 혼합비를 40배로 하였을 때 가장 좋은 들뜸조건을 얻을 수 있었다. 분석 결과의 표준편차는 $SiO_2$는 1.3%, $ZrO_2$는 4.9%였다.

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Introgression of Sex-Limited Larval Markings to a Productive Multivoltine Strain of Silkworm Bombyx mori L.

  • Rao, D. Raghavendra;Singh Ravindra;Basavaraja H.K.;Kariappa B.K.;Dandin S.B.;Rufaie S.Z. Haque
    • International Journal of Industrial Entomology and Biomaterials
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    • 제13권1호
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    • pp.7-14
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    • 2006
  • A breeding programme was initiated during 2001 to introduce sex-limited larval markings to a productive multivoltine breed - BL67 from an inbred sex-limited line, MY1 (SL) maintained at Central Sericultural Research and Training Institute, Mysore. Introgressive hybridization, recurrent backcrossing for six generations followed by sib-mating resulted in synthesis of a new multivoltine silkworm breed BL67 (SL) with sex-limited larval markings. The new breed was studied for combining ability by crossing with eight bivoltine breeds viz., $NB_4D_2,\;CSR_2,\;CSR_2 (SL),\;CSR_2,\;CSR_4,\;CSR_8,\;CSR_{18}\;and\;CSR_{19}$. General combining ability effects of the new breed showed its superiority over the popular Pure Mysore by expressing significant GCA effects for six out of twelve characters whereas the results are on par with the original multivoltine breed. The hybrid $BL67(SL){\times}CSR2(SL)$ excelled in several quantitative characters such as pupation rate (90.2%), cocoon weight (1.97 g), cocoon shell weight (40 cg), cocoon shell ratio (20.3%), filament length (918 m), denier (2.96), raw silk percentage (14.96%) and neatness (90 p). Studies on cocoon size variability revealed that the cocoons of $BL67(SL){\times}CSR2(SL)$ were found comparatively uniform showing less standard deviation of 6.55 and co-efficient of variation of 3.91 %. The suitability of newly developed breed for easy grain age operation and commercial exploitation with promising hybrid have been discussed.

Evaluation of Mixtures of Certain Market Wastes as Silage

  • Ozkul, H.;Kilic, A.;Polat, M.
    • Asian-Australasian Journal of Animal Sciences
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    • 제24권9호
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    • pp.1243-1248
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    • 2011
  • The aim of this study was to determine the usefulness of vegetable wastes as silage for ruminants. Varying amounts of wheat straw (WS), wheat bran (WB) and salt (S) were combined with minced vegetable wastes (VW) during ensilage. Seven different ingredient combinations were investigated viz: 100% VW (Group I, control), 90% VW+9% WS+1% S (Group II), 80% VW+15% WS+4% WB+1% S (Group III), 70% VW+20% WS+9% WB+1% S (Group IV), 90% VW+9% WB+1% S (Group V), 80% VW+15% WB+4% WS+1% S (Group VI) and 70% VW+20% WB+9% WS+1% S (Group VII). The inclusion of straw and bran increased (p<0.01) the DM content of silage. The highest contents of the pure silage were CP (p<0.001), EE (p<0.01) and NFE (p<0.05). NDF contents of VW silage and group V were significantly lower and especially the VW silage was found to have the lowest ADL content (p<0.01). The in vitro ME values of VW silage and bran added silage were higher than other groups (p<0.01). pH, lactic acid and acetic acid values of silage groups were changed between 4.09-4.20, 2.43-3.46% and 0.60-0.86%, respectively. In conclusion, different mixtures of VW have a high ensilage capacity and can serve as an alternative roughage source for ruminants. The addition of 9% bran significantly improved the silage in view of both dry matter content and nutritive value.

들깨 잎 추출물의 Nitric Oxide Synthase 저해활성 및 Peroxynitrite 소거활성 (Inhibitory Activity of Nitric Oxide Synthase and Peroxynitrite Scavenging Activity of Extracts of Perilla frutescens)

  • 김재연;김지선;정찬식;진창배;류재하
    • 생약학회지
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    • 제38권2호통권149호
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    • pp.170-175
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    • 2007
  • Activated microglia by neuronal injury or inflammatory stimulation overproduce nitric oxide (NO) by inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS) such as superoxide anion, resulting in neurodegenerative diseases. The toxic peroxynitrite (ONOO$^-$), the reaction product of NO and superoxide anion further contributes to oxidative neurotoxicity. We tried to evaluate the effects of two kinds of varieties of Perilla frutescens var japnica Hara on the NO production in lipopolysaccharide (LPS)-activated microglia. The perilla cultivars of Namcheondeulkkae (NC) and Boradeulkkae (BR) were developed by pure line from the local variety and by a cross between 'deulkkae' and 'chajogi', respectively. Spirit, hexane, chloroform and butanol fractions of the leaves of NC and BR inhibited the production of NO in LPS-activated microglia. The fractions of BR showed stronger activity than NC and the spirit extracts was the most potent in both cultivars. The solvent fractions of BR suppressed the expression of protein and mRNA of iNOS in LPS-activated microglial cells. Moreover, the extracts of NC and BR showed the activity of peroxynitrite scavenging in cell free bioassay system. These results imply that Namcheondeulkkae and Boradeulkkae might have neuroprotective activity through the inhibition of NO production by activated microglial cells and peroxynitrite scavenging activity.

시간 마스킹이 음상정위에 미치는 영향 (The effects of a temporal masking on the sound laterlization)

  • 이채봉
    • 한국전자통신학회논문지
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    • 제5권4호
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    • pp.352-356
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    • 2010
  • 본 연구에서는 선행음과 후속음의 영향이 음상정위에 어떠한 영향을 미치는지에 대하여 실험을 하였다. 음원은 양귀간 시간차(Interaural Time Difference ; ITD)를 0.5ms로 한 기준음을 사용하였다. 이러한 기준음과 5종류의 레벨차를 가진 방해음(선행음 및 후속음) 및 기준음과 방해음의 시간차(Inter-Stimuli Interval ; ISI) 4종류를 조합하여 피실험자에게 제공하였다. 그리고 주파수에 대한 의존성을 알아보기 위해 기준음과 방해음을 2kHz, 4kHz, 백색 잡음을 이용하였다. 피실험자는 헤드폰을 사용하여 기준음이 좌우 어느 쪽에서 들리는지를 판단하도록 하였다. 그 결과 음상정위에 미치는 영향은 후속음보다는 선행음이 크게 나타났다. 이것은 시간 마스킹과 같은 경향이라고 생각되어 진다. 음상정위에 있어서는 기준음과 방해음 사이의 주파수 의존성은 적게 나타났다.

CrOx/TiO2 촉매의 결정성과 TCE 산화반응 활성 (Crystallinity of CrOx/TiO2 Catalysts and Their Activity in TCE Oxidation)

  • 김문현;이효상
    • 한국환경과학회지
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    • 제23권5호
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    • pp.829-837
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    • 2014
  • Titania-supported chromium oxides with different loadings have been embarked in catalytic oxidation of trichloroethylene (TCE) to inquire association of the formation of crystalline $Cr_2O_3$ with catalytic performances. A better activity in the oxidative TCE decomposition at chosen temperatures was represented when chromium oxides ($CrO_x$) had been dispersed on pure anatase-type $TiO_2$ (DT51D) rather than on phase-mixed and sulfur-contained ones such as P25 and DT51. The extent of TCE oxidation at temperatures below $350^{\circ}C$ was a strong function of $CrO_x$ content in $CrO_x$/DT51D $TiO_2$, and a noticeable point was that the catalyst has two optimal $CrO_x$ loadings in which the lowest $T_{50}$ and $T_{90}$ values were measured for the TCE oxidation. This behavior in the activity with respect to $CrO_x$ amounts could be associated with the formation of crystalline $Cr_2O_3$ on the support surface, that is less active for the oxidation reaction, and an easier mobility of the surface oxygen existing in noncrystalline $CrO_x$ species with higher oxidation states, such as $Cr_2O_8$ and $CrO_3$.

선포토미터 데이터를 이용한 편광소멸도 산출과 라이다 편광소멸도와의 비교 (Retrieval of Depolarization ratio using Sunphotometer data and Comparison with LIDAR Depolarization ratio)

  • 김관철;최성철;노영민
    • 대한원격탐사학회지
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    • 제32권2호
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    • pp.97-104
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    • 2016
  • 본 연구에서는 일본 오사카에서 AERONET 선포토미터로 관측된 데이터를 분석하여 440, 675, 870, 1020 nm 파장에서의 입자 편광소멸도를 산출하였다. 산출된 결과는 같은 지역에서 측정된 라이다 자료로부터 얻어진 532 nm에서의 입자 편광소멸도와 비교하였다. 두 값은 440 nm를 제외하고는 잘 일치되는 결과를 보였고, 상관계수($R^2$)는 440, 675, 870, 1020 nm에서 각각 0.28, 0.81, 0.88 0.89의 값을 보였다. 가장 높은 상관계수를 보인 1020 nm에서의 입자 편광소멸도를 기준으로 값의 변화에 따른 입자의 혼합정도를 확인하였을 때, 순수 황사의 경우 높은 편광소멸도를 보이고 오염입자가 혼합될수록 값이 낮아짐을 보였다. 이는 단산란 알베도와 입자 크기 분포를 통하여 확인하였다.

고체분산체 및 포접화합물을 이용한 난용성 약물인 이부프로펜의 용출 속도의 증가 (Enhancement of Dissolution Rate of Poorly Water-soluble Ibuprofen using Solid Dispersions and Inclusion Complex)

  • 이범진;이태섭
    • Journal of Pharmaceutical Investigation
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    • 제25권1호
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    • pp.31-36
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    • 1995
  • Solid dispersions and inclusion complex were prepared for the enhancement of solubility and dissolution rate of poorly water-soluble ibuprofen(IPF) as a model drug. Polyethylene glycol 4000(PEG4000) and polyvinylpyrrolidone(PVP) were used for the preparation of solid dispersion. $2-Hydroxypropyl-{\beta}-cyclodextrin(2-HP{\beta}CD)$ was also used for the preparation of inclusion complex. The solubility of IPF increased as the concentration of PEG4000, PVP and $2-HP{\beta}CD$ increased. Solubilization capacity of $2-HP{\beta}CD$ was increased about 10 times when compared to PEG 4000 and PVP. The dissolution rate of drug from solid dispersions and inclusion complex in the simulated gastric fluid was enhanced when compared to pure IPF and commercial $BR4^{\circledR}$ tablet as a result of improvement of solubility. In case of solid dispersions, dissolution rate of drug was proportional to polymer concentration in the formulation. The marked enhancement of dissolution rate of drug by inclusion complexation with $2-HP{\beta}CD$ was noted. However, dissolution rate of drug from solid dispersions and inclusion complex in the simulated intestinal fluid was not significant because IPF was readily soluble in that condition. From these findings, water-soluble polymers and cyclodextrin were useful to improve solubility and dissolution rate of poorly water-soluble drugs. However, easiness and reliability of preparation method, scale-up and cost of raw materials must be considered for the practical application of solid dispersion and inclusion complex in pharmaceutical industry.

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