• Asian-Australasian Journal of Animal Sciences
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• 제21권8호
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• pp.1220-1225
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• 2008

This study was conducted to investigate the protective effect of genistein on the antioxidative defence system and membrane fluidity in chick skeletal muscle cells after supplementation with 0, 20, 40, and $80{\mu}mol/L$ genistein in $50{\mu}mol/L$ $FeSO_4/H_2O_2$ treated cells for 24 h. Genistein supplementation recovered the decreased activity of total superoxide dismutase induced by $FeSO_4/H_2O_2$, significantly increased glutathione peroxidase activity (p<0.05) and decreased malondialdehyde production (p<0.05). The treatment of 80 mol/L genistein in $FeSO_4/H_2O_2$ treated cells decreased the secretion of creatine kinase (p<0.05). Fluorescence polarization values and microviscosities observed with $FeSO_4/H_2O_2$ treated cells were significantly higher than those observed with no $FeSO_4/H_2O_2$ treated cells. The addition of $80{\mu}mol/L$ genistein improved the increased fluorescence polarization value (p<0.05) caused by $FeSO_4/H_2O_2$ treatment. The microviscosity value was significantly decreased by adding genistein (p<0.05). In conclusion, genistein protected skeletal muscle cells from oxidative damage by improving antioxidative status and membrane fluidity.

• 생명과학회지
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• 제9권4호
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• pp.473-480
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• 1999

This study was designed to investigate the effects of pine (Pinus densiflora Sieb et Zucc) needle extract (PNE) on membrane fluidity and oxidative stress in liver membranes of Sprague-Dawley (SD) rats as a study on investigation of anti-aging effect and determination of chemical structures of PNE through the animal experiments. Male SD rats were fed basic diets (control group) and experimental diets (0.5% and 1.0%-PNE group) for 6 weeks. Administrations of 0.5% and 1.0%-PNE resulted in a marked decreases (15∼25% and 23∼26%, respectively) in cholesterol accumulations of liver mitochondria and microsomes compared with control group. Membrane fluidities were significantly increased (15∼25%) in liver microsomes of 0.5% and 1.0%-PNE groups compared with control group. Formations of basal and induced oxygen radicals (BOR and IOR) in liver mitochondria were significantly inhibited (11∼12% and 10∼15%, respectively) by administrations of 0.5% and 1.0%-PNE compared with control group. Lipid peroxide (LPO) levels were remarkbly decreased about 20% in liver mitochondria and microsomes of 0.5% and 1.0%-PNE groups compared with control group. Oxidized protein levels calculated with carbonyl group were significantly decreased about 15% in liver mitochondria of 1.0%-PNE group compared with control group. These results suggest that PNE may play a effective role in a attenuating a oxidative stress and increasing a membrane fluidity.

• 한국세라믹학회지
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• 제44권1호
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• pp.6-11
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• 2007

The rheological properties of slag cement pastes by effect of particle size distribution of binder were investigated using a Rheostress 1 rheometer (Haake) with a cylindrical spindle and the relationship between fluidity particle size distribution using the Rosin-Rammler equation. Samples are combined the two types of slag powder and OPC, fine slag particles sized Elaine specific surface area $8,000cm^2/g$, coarse slag particles sized Elaine specific surface area $2,000cm^2/g$, intermediate OPC particles $3,450cm^2/g$, used to search for the combination that would yield the best quality product. The all flow curves which were measured by rheometer showed hysterisis and could be classified into 4 types. When the combination was based on a ratio of 15-20 vol% fine particles, 40-50 vol% intermediate particles, 30-40 vol% coarse particles of the total volume, a high fluidity and low yield-strength was achieved. The Rosin-Rammler function can explain aboved correlation flow curve types. On type 1, the n-value had a correlation with plastic viscosity however the blend of type 2 and 3 showed consistent n-value regardless of plastic viscosity. In addition, the blend in type 4 tended to a rise in fluidity according to the increase of the n-value.

• The Korean Journal of Physiology and Pharmacology
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• 제16권6호
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• pp.413-422
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• 2012

The purpose of this study is to investigated the mechanism of pharmacological action of local anesthetic and provide the basic information about the development of new effective local anesthetics. Fluorescent probe techniques were used to evaluate the effect of lidocaine HCl on the physical properties (transbilayer asymmetric lateral and rotational mobility, annular lipid fluidity and protein distribution) of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex, and liposomes of total lipids (SPMVTL) and phospholipids (SPMVPL) extracted from the SPMV. An experimental procedure was used based on selective quenching of 1,3-di(1-pyrenyl)propane (Py-3-Py) and 1,6-diphenyl-1,3,5-hexatriene (DPH) by trinitrophenyl groups, and radiationless energy transfer from the tryptophans of membrane proteins to Py-3-Py. Lidocaine HCl increased the bulk lateral and rotational mobility of neuronal and model membrane lipid bilayes, and had a greater fluidizing effect on the inner monolayer than the outer monolayer. Lidocaine HCl increased annular lipid fluidity in SPMV lipid bilayers. It also caused membrane proteins to cluster. The most important finding of this study is that there is far greater increase in annular lipid fluidity than that in lateral and rotational mobilities by lidocaine HCl. Lidocaine HCl alters the stereo or dynamics of the proteins in the lipid bilayers by combining with lipids, especially with the annular lipids. In conclusion, the present data suggest that lidocaine, in addition to its direct interaction with proteins, concurrently interacts with membrane lipids, fluidizing the membrane, and thus inducing conformational changes of proteins known to be intimately associated with membrane lipid.

• Molecules and Cells
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• 제19권3호
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• pp.356-364
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• 2005

Intramolecular excimer formation of 1,3-di(1-pyrenyl) propane(Py-3-Py) and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to evaluate the effect of ethanol on the rate and range of lateral and rotational mobilities of bulk bilayer structures of synaptosomal plasma membrane vesicles (SPMVs) from the bovine cerebral cortex. Ethanol increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py in the SPMVs. Selective quenching of both DPH and Py-3-Py by trinitrophenyl groups was used to examine the range of transbilayer asymmetric rotational mobility and the rate and range of transbilayer asymmetric lateral mobility of SPMVs. Ethanol increased the rotational and lateral mobility of the outer monolayer more than of the inner one. Thus ethanol has a selective fluidizing effect within the transbilayer domains of the SPMVs. Radiationless energy transfer from the tryptophans of membrane proteins to Py-3-Py was used to examine both the effect of ethanol on annular lipid fluidity and protein distribution in the SPMVs. Ethanol increased annular lipid fluidity and also caused membrane proteins to cluster. These effects on neuronal membranes may be responsible for some, though not all, of the general anesthetic actions of ethanol.

• 공업화학
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• 제9권3호
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• pp.336-341
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• 1998

II형 무수석고의 평균 입경과 치환율이 시멘트페이스트의 유동성에 미치는 영향에 대해 비교하였다. 나프탈렌계(NSF)와 폴리카르본산계(NT-2) 등 2가지 고유동화제의 첨가량을 0~2.0wt%으로 변화시켰을 때 3종으로 구분한 II형 무수석고의 평균입경(4, 14, $35{\mu}m$)과 치환율(3, 5, 10, 15wt%)의 변화에 따른 영향을 측정하였다. 이들 변수들에 따른 영향을 측정하기 위하여 시멘트페이스트의 초기 유동성 및 경과시간별로 겉보기 점도를 관찰하였다. 시멘페이스트의 초기유동성은 II형 무수석고의 평균입경에 의한 영향보다는 II형 무수석고의 치환율 증가에 의한 영향이 더욱 큰 것으로 나타났다. II형 무수석고의 치환율을 10wt%로 고정시 NT-2, 1.0wt% 첨가로 시멘트페이스트의 유동성은 동일 첨가량의 NSF보다 크게 향상되었다. 이는 측정된 변수들의 범위 중에서 가장 우수한 시멘트 페이스트의 유동성을 보여주는 경우이다. NT-2, 1.0wt% 첨가에서 II형 무수석고의 치환율 증가에 따라 시멘트 페이스트의 겉보기 점도가 현저하게 감소되었다. 이로부터 시멘트 페이스트의 유동성 향상을 위해서는 NT-2의 첨가와 더불어 시멘트를 II형 무수석고로 일정비율 치환하는 것이 더욱 효과적임을 알 수 있었다.

• 한국산학기술학회논문지
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• 제18권2호
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• pp.689-696
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• 2017

기존의 고유동 콘크리트는 높은 분체계로 인해 수화열과 수축의 증대, 비경제적인 강도발현 등의 문제점이 발생하여 일반강도 범위의 콘크리트에는 사용범위가 제한하고 있다. 그러나 공사품질의 향상과 더불어 공사비 절감, 공기단축 등의 이점으로 일반강도 수준의 고유동 콘크리트의 필요성이 대두되고 있다. 이를 위해 본 연구에서는 점성을 최소화하고 재료분리 저항성은 극대화 된 저분체 고유동 콘크리트를 제조하기 위하여 적절한 증점제의 사용방법과 최적 배합을 검토하고 제조 된 콘크리트의 특성을 검토하였다. 다양한 증점제를 대상으로 역학적 특성 평가를 통해 저분체 고유동 콘크리트 제조에 적합한 증점제를 선정하였으며, 그 결과 아크릴계(Acrylic. 이하 AC) 및 우레탄계(Urethane, 이하 UT) 증점제가 재료분리가 발생 하지 않는 범위에서 가장 우수한 성능을 나타내어 가장 적합한 것으로 나타났다. 선정된 AC 및 UT 증점제의 최적 혼입량을 검토하기 위하여 두 물질의 혼합사용 및 고성능 감수제와 일액화를 통한 배합실험을 하였으며, 그 결과 AC 및 UT 증점제의 비율이 5:5인 경우 유동성 증대 및 점성 저감 효과가 증가함에 따라 저분체 고유동 콘크리트에 가장 적합한 것으로 나타났다.

• 한국세라믹학회지
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• 제39권2호
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• pp.178-183
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• 2002

금속염으로 산화아연(ZnO)과 규불화수소산($H_2SiF_6$)을 이용하여 용액법으로 규불화아연($ZnSiF_6$, 농도 15%)을 제조하고 이를 시멘트용 혼화제로 첨가하여 시멘트의 유동성과 수화특성에 미치는 영향을 파악하였다. 규불화아연의 첨가량을 시멘트량 대비 1.0∼4.0%로 증가시켜 첨가한 시멘트 페이스트의 초기 유동성과 유동성의 경시변화를 측정하였다. 초기 유동성은 mini-slump 시험을 통해 평가하였고, 유동성의 경시변화는 slump loss 시험을 통해 평가하였다. 또한 규불화아연을 시멘트에 1.0∼3.0%로 첨가하였을 때 시멘트의 응결시간에 미치는 영향과 시멘트 수화열 변화에 미치는 영향을 파악하였다. 시멘트 페이스트의 유동성은 규불화아연이 2.1% 첨가되었을 때 가장 높게 나타났으나 경시변화는 다소 큰 것으로 나타났다. 시멘트 응결시간은 규불화아연의 첨가량 증가에 따라 지연되는 특성을 보였으며, 시멘트 수화열은 첨가량에 비례하여 감소되는 경향을 보였다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2004년도 학술대회지
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• pp.51-54
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• 2004

This paper investigated the results of mixture proportion and compressive strength of concrete incorporating mineral admixtures. W/B and contents of mineral admixtures were selected as test parameters. According to test results, use of mineral admixtures resulted in a reduction of fluidity and air contents caused by increased fine particles and absorption effect of FA on reduction of AE agent. Thus, increase of SP and AE agent was needed to maintain the same fluidity and air content as plain concrete. At early stage, use of CKD was beneficial to the compressive strength while at 28days. incorporation of FA and BS had favorable effect on the compressive strength.

• Archives of Pharmacal Research
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• 제17권3호
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• pp.182-189
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• 1994

The effect of lipophilicity on the mechanisms of drug absorption through biomembranes was investigated empolying HPLC system and the fluorescence technique. Human erythrocyte ghost membranes were used as a model biomembrane. A series of four parabens (methyl, ethyl, rpopyl, and butyl) and p-hydroxybenzoic acid were used as the model drugs for lipophilicities and their partition coefficients were measured in Sorensen's phosphate buffer solution (pH 5)/octanol system. Absorption amount of parabens through erythrocyte ghost membranes increased with an increase of lipophilicity resulted from the addition of methylene group to the n-alkyl chain of parabens. And the effect of parabens on the fluidity of ghost membrane also increased with an increase of their lipophilicities.