• 제목/요약/키워드: Release fraction

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Physiological and Whitening Effects of Morus alba Extracts

  • Gug, Kyungmee
    • 통합자연과학논문집
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    • 제5권1호
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    • pp.46-52
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    • 2012
  • Mulberry extracts can be incorporated into skin-whitening products. The compound attributed to lighten the skin is arbutin, a form of hydroquinone that inhibits melanin release by suppressing the tyrosinase enzyme. For the cosmetic applications, the physiological effects of mulberry (Morus alba) extracts were investigated. The water soluble fraction of mulberry contains higher amount of protein (16.28~4.47%) in contrast to fat (1.55~1.41%). In addition, the fraction abundantly contains succinic acid (972.4-275.8 mg/g) and phosphoric acid (1,628.4-121.9 mg/g) in different parts of mulberry. The free radical scavenging ability in water soluble fraction was found to display remarkable effects in comparison with methanol and ethyl acetate fraction. The ethyl acetate-soluble of root and leaf showed remarkable tyrosinase inhibition activity by IC 50 (${\mu}g/ml$). The anticancer activity of methanol fraction obtained from mulberry using human cancer cell lines showed growth inhibition effect (270.14 mg/ml in Calu-6 cells, 295.29 mg/ml in HCT-116, and 332.29 mg/ml in MCF-7 cells, respectively). Based on the results, Morus alba extracts include cosmetic ingredients with antioxidizing and whitening properties.

히드록시프로필셀룰로오스/카르보폴 고체분산체의 점막부착성과 팽윤 및 약물방출특성 (Mucoadhesion, Swelling and Drug Release Characteristics of Hydroxypropylcellulose/Carbopol Solid Dispersions)

  • 김상헌;양수근;신동선;이민석;최영욱
    • Journal of Pharmaceutical Investigation
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    • 제24권3호
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    • pp.155-165
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    • 1994
  • Some mucoadhesive polymers such as hydroxypropylcelluose (HPC) and carbopol-934 (CP) have been employed for the preparation of mucoadhesive polymeric systems, and their physical properties including mucoadhesion, swelling, and drug release were evaluated. A new simple experimental technique that can quantitatively measure the bioadhesive properties of various polymeric systems has been developed by the methods of detachment force test. As the polymeric systems, the discs of freeze-dried HPC/CP solid dispersions were prepared. The mucosa used in these tests were upper, middle, and lower parts of small intestine of male rats weighing $300{\sim}350\;g$. Detachment forces were increased as the mole fraction of CP increased in discs of HPC/CP solid dispersions. In the points of intestinal site dependence of mucoadhesion, the solid dispersions revealed non-specific mucoadhesion to the intestine. Swelling and drug release characteristics of mucoadhesive polymeric systems were studied extensively to find out the feasibility for the oral controlled delivery systems. Swelling ratio, expressed as the final height/initial height, has been determined in various pH buffer solutions. Hydrochlorothiazide (HCT) was employed as a model drug for release study. Apparent swelling and drug release rate constants, $K_s$ and $K_r$ respectively, were obtained from the square-root time plot of either swelling ratio or released amount of drug, particularly for the time periods before reaching the equilibrium. As a result, the swelling ratio of HPC/CP solid dispersions was increased as the weight percentage of CP increased. Similarly, the release of HCT from the solid dispersions was dependent on pH changes and CP contents, resulted in the slower release of HCT with the increases of pH and CP contents.

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상엽의 혈당강하 활성 (Blood Glucose-Lowering Effects of Mori Folium)

  • 이주선;최명현;정성현
    • 약학회지
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    • 제39권4호
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    • pp.367-372
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    • 1995
  • Mori Folium(MF) methanol extract and its water soluble fraction showed significant blood glucose lowering effects alloxan-induced hyperglycemic mice. Their hypoglycemic activities seemed to nothing to do with the stimulation of insulin release or insulin-like action, according to our experiments. On the other hand, MF prevents the hyperglycemic responses from an oral load of starch and glucose in vivo. Since complex carbohydrates present in a diet must be degraded to monosaccharides by $\alpha$-glucohydrolase before being absorbed in the gastrointestinal tract, it is thought that blood glucose lowering effects of MF may be related to the inhibition of $\alpha$-glucohydrolase catalyzed enzymatic reaction. In addition, experiments that examined an effect of MF water soluble fraction on gastrointestinal movement showed no significant GI movement inhibitory effect. In conclusion, MF water soluble fraction may possess active component which is a potential candidate as an orally active agent for the treatment of diabetes mellitus.

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Enhancement of nerve growth factor production and release by buthanol fraction of Liriope platyphylla in C6 cells and rat cultured astrocyte

  • Hur, Jin-Young;Lee, Pyeong-Jae;Kim, Jeong-Min;Kim, Ho-Cheol;Kim, Sun-Yeou
    • 대한약학회:학술대회논문집
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    • 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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    • pp.135.3-136
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    • 2003
  • Liriope platyphylla (LP) Wang et Tang has been used for tonic, anti-tussive and expectorant in Korea. In the current study, we found that buthanol fraction of Liriope platyphylla-conditioned media of C6 and primary astrocyte induced the neurite outgrowth of PC 12 cells, which effect was reversed by addition of NGF-antibody. We demonstrated that buthanol fraction of Liriope platyphylla increased the expression and secretion of NGF through RT-PCR and ELISA. (omitted)

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강-열점소성 유한요소법을 이용한 반용융단조시 성형인자들의 영향에 관한 연구 (A Study on Effect of Forming Parameters in Semi-Solid Forging by Rigid-Thermoviscoplastic Finite Element Method)

  • 윤종훈;김낙수;임용택;이준두
    • 한국소성가공학회:학술대회논문집
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    • 한국소성가공학회 1998년도 춘계학술대회논문집
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    • pp.179-184
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    • 1998
  • Semi-solid forging can be applied in industry only with enough knowledge of the effects of the forming parameters related with the process and their exact control which can be obtained by empirical or numerical methods. In the current study, the effects of process variables on semi-solid forging are discussed based on mainly numerical results. Die preheating temperature, initial solid fraction of the workpiece, and die velocity were selected as process variables, and numerical analyses using a rigid-thermoviscoplastic finite element approach that considered the release of latent heat due to phase change were carried out. In the analyses, a proposed flow stress material characterization and a solid fraction updating algorithm were employed. The obtained results from numerical analysis are discussed and are compared with some experimental observations.

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입자강화 복합재료의 파괴인성에 관한 프랙탈 해석 (Fractal analysis on fracture toughness of particulate composites)

  • 김엄기;남승훈;고성위
    • 한국해양공학회지
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    • 제10권4호
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    • pp.84-91
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    • 1996
  • A fractal analysis on fracture surface of aluminium-particulate SiC composites was attempted. As the volume fraction of SiC in composites increases, the fractal dimension tends to increase. However, no correlation between the fractal dimension and the fracture toughness in terms of critical energy release rate was observed. Since the fractal dimension represents the roughness of fracture surface, the fracture toughness would be a function of not only fracture surface roughness but also additional parameters. Thus the applicability of fractal analysis to the estimation of fracture toughness must depend on the proper choice and interpretation of additioal paramerters. In this paper, the size of characteristic strctural unit for fracture was considered as an additional parameter. As a result, the size appeared to be a function of only volume fraction of SiC. Finally, a master curve for fracture toughness of aluminium-particulate SiC composites was proposed as a function of fractal dimension and volume fraction of SiC.

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사향(麝香)의 수용성분(水容性分)이 생쥐 복강내(腹腔內) 거식세포(巨食細胞)의 활성(活性)에 미치는 영향(影響) (Effects of the water soluble fraction of the musk on the activities of murine peritoneal macrophages)

  • 임석린
    • 대한예방한의학회지
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    • 제6권2호
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    • pp.147-155
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    • 2002
  • The musk has been reported to have significant anti-inflammatory activities in clinical use and several animal models and we examined the effects of water soluble fraction(WSF) of the musk on murine peritoneal macrophages. WSF decreased the production of nitric oxide from the lipopolysaccharide(LPS)-treated murine peritoneal macrophages and also reduced the phagocytic activity of macrophages on the opsonized sheep red blood cells(SRBC). Transcriptional expression level of the inducible nitric oxide synthase(iNOS) was also decreased and the viability of the treated macrophages was not affected by WSF, suggesting that the effects could be partly explained by transcriptional regulation. Contrary to down-regulating iNOS expression, WSF slightly increased the release of tumor necrosis factor-alpha$(TNF-{\alpha})$, which implied its selective action on cellular pathways activated by LPS. Our results showed that anti-inflammatory activities of the musk could be partly explained by the inhibitory effects of the water soluble fraction on the macrophageal activation.

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층상연료분사(경유/메탄올)를 이용한 디젤엔진의 NOx와 Soot 동시 저감에 관한 연구 (제1보 : 층상분사장치의 설계 및 층상분사 연소특성) (A Study on the Simultaneous Reduction of NOx and Soot with Diesel-Methanol Stratified Injection System in a Diesel Engine (Part I : Design of Stratified Injection System and Combustion Characteristics of Stratified Injection))

  • 강병무;김종률;이선봉;이태원;하종률
    • 한국분무공학회지
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    • 제5권2호
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    • pp.28-34
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    • 2000
  • To reduce the soot and NOx simultaneously, a new system of stratified injection is developed. This system discharges stratified diesel-methanol in a D. I. Diesel Engine. Nozzle and delivery valve of conventional injection system were remodeled to inject diesel and methanol from one injector sequently. The quantity of diesel and methanol was controled precisely by micrometers mounted on the injection control lack. The real injection ratio of dual fuel was measured by volumetric ratio. We could confirm the capabilities that soot and NOx simultaneously were reduced by diesel-methanol stratified injection from the results of in-cylinder pressure data obtained from combustion experiment by stratified injection, heat release rate and mass fraction bumed.

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온도변화에 따른 나노 복합재료의 충격거동 (Impact behavior on temperature effect of nano composite materials)

  • 김형진;이정규;고성위
    • 수산해양기술연구
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    • 제51권4호
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    • pp.561-566
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    • 2015
  • In this study, the effect of temperature effect of the rubber matrix filled with nano sized silica particles composites with silica volume fraction of 19-25% was investigated by the Charpy impact test. The Charpy impact test was conducted in the temperature range from $-40^{\circ}C$ to $0^{\circ}C$. The critical energy release rate GIC of the rubber matrix composites filled with nano sized silica particles was considerably affected by temperature and it was shown that the maximum value was appeared at higher temperature between temperature tested and it was shown that the value of GIC increases as temperature tested increases. The major fracture mechanisms were matrix deformation, silica particle debonding and delamination, microcrack between particles and matrix, and/or pull out between particles and matrix which is ascertained by SEM photographs of Charpy impact surfaces fracture.

Affinity of transducin for photoactivated rhodopsin: dependence on nucleotide binding state

  • Clack, James W.
    • BMB Reports
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    • 제41권7호
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    • pp.555-560
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    • 2008
  • The interaction of the rod GTP binding protein, Transducin ($G_t$), with bleached Rhodopsin ($R^*$) was investigated by measuring radiolabeled guanine nucleotide binding to and release from soluble and/or membrane-bound Gt by reconstituting $G_t$ containing bound GDP ($G_t$-GDP) or the hydrolysis-resistant GTP analog guanylyl imidodiphosphate ($G_t$-p[NH]ppG) with $R^*$ under physiological conditions. Release of GDP and p[NH]ppG from $G_t$ occurred to the same extent and with the same light sensitivity both in the presence and absence of added GTP. Significant amounts of $G_t$ without bound nucleotide ($G_{t^-}$) were generated. When ROS containing bleached rhodopsin ($R^*$) were centrifuged in low ionic strength buffer, $G_{t^-}$ remained associated with the membrane fraction, whereas $G_t$-GDP remained in the soluble fraction. These results suggest that $G_t$-GDP and $G_t$-p[NH]ppG have similar affinities for $R^*$. The results also suggest that $G_{t^-}$, rather than $G_t$-GDP, is the moiety which exhibits tight, "light-induced" binding to rhodopsin.