• 제목/요약/키워드: influx

검색결과 1,033건 처리시간 0.03초

고압벽돌의 백화원인에 대한 기초적 연구 (Fundamental Study on the Cause of Efflorescence in Calciumsilicate Brick)

  • 한상목;신건철
    • 산업기술연구
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    • 제2권
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    • pp.61-67
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    • 1982
  • The cause of efflorescence originated from calciumsilicate hydrate brick was studied and some reports on efflorescence were reviewed. The main ingredient of undesirable efflorescence powder was sodium sulphate. It was found that influx of sodium and sulphur components was resulted from hydration water and fine sand.

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인체적혈구막(人體赤血球膜) 안정화(安定化)에 미치는 인지질(燐脂質)의 영향(影響) (The Stabilizing Effects of Phospholipids on the Human Erythrocyte Membranes)

  • 김용기;김재백
    • Journal of Pharmaceutical Investigation
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    • 제11권2호
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    • pp.1-10
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    • 1981
  • Phospholipids were examined for their capacity to protect human erythrocytes against hemolysis induced by hypotonic solution, p-hydroxymercuribenzoate or hematin. The following results were obtained. 1. Phosphatidyl choline, lysophosphatidyl choline and phophatidyl ethanoleamine as well as chlorpromazine prevented the osmotic hemolysis of human erythrocytes which occurred due to water influx into erythrocytes from medium, but showed no effect on hematin-induced hemolysis which occurred without the volume change of erythrocytes. 2. Human erythrocytes were found to be most sensitive to the antihemolytic action of phospholipids among mammalian erythrocytes from sheep, rabbit, rat and mouse. 3. Phospholipids at the concentrations showing their strong antihemolytic effect on human erythrocytes against osmotic hemolysis had no influence on methylene blue uptake and volume change of erythrocytes in hypotonic solution. 4. Phospholipids increased erythrocyte deformability 2 to 3 times over control group and there was aclose relationship between their antihemolytic action and increase of deformability as a function of their concentrations. 5. The phospholipids increased the resistance to osmotic hemolysis of human erythrocytes by increasing membrane elasticity through their incorporation into lipid bilayer without altering glucose metabolism and water influx to erythrocytes.

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에이코사펜타에노익산에 의한 세포 내에서의 지방 축적 억제 효과 및 포도당 대사에 관여하는 전사인자의 변화 (Effect of Eicosapentaenoic Acid on Cellular Lipid Accumulation and Transcription Factors Involving Glucose Utilization)

  • 부소영
    • 한국식품영양학회지
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    • 제24권4호
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    • pp.501-508
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    • 2011
  • Previous studies suggest that polyunsaturated fatty acids with long carbon chains such as eicosapentaenoic acid(EPA) and docosahexaenoic acid(DHA) have several health benefits. However metabolic consequences of these fatty acids themselves and their regulation of transcriptional activity involving glucose utilization are not well established. Thus, the purpose of this study was to investigate how EPA influx affects cellular lipid accumulation and gene expressions involving $de$ $novo$ lipogenesis in hepatocyte cultures. Compared to oleic acid treatment, EPA treatment showed remarkably decreased cellular TG conversion and accumulation, along with phospholipids at a lower extent. As expected, EPA increased mRNA expression involving fatty acid influx and lipid droplet formation, but did not affect mRNA expression involving glucose utilization. EPA increased transcriptional activity of PPAR-${\alpha}$ and glucose responsive transcription factor when transcription factor binding protein was activated. Taken together, these data suggest that EPA decreases lipid accumulation through increases of the ${\beta}$-oxidation pathway without interruption of glucose utilization.

Epac2 contributes to PACAP-induced astrocytic differentiation through calcium ion influx in neural precursor cells

  • Seo, Hyunhyo;Lee, Kyungmin
    • BMB Reports
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    • 제49권2호
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    • pp.128-133
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    • 2016
  • Astrocytes play a critical role in normal brain functions and maintaining the brain microenvironment, and defects in astrocytogenesis during neurodevelopment could give rise to severe mental illness and psychiatric disorders. During neuro-embryogenesis, astrocytogenesis involves astrocytic differentiation of neural precursor cells (NPCs) induced by signals from ciliary neurotrophic factor (CNTF) or pituitary adenylate cyclase-activating peptide (PACAP). However, in contrast to the CNTF signaling pathway, the exact mechanism underlying astrocytic differentiation induced by PACAP is unknown. In the present study, we aimed to verify a signaling pathway specific to PACAP-induced astrocytogenesis, using exchange protein directly activated by cAMP2 (Epac2)-knockout mice. We found that PACAP could trigger astrocytic differentiation of NPCs via Epac2 activation and an increase in the intracellular calcium concentration via a calcium ion influx. Taken together, we concluded that astrocytogenesis stimulated by PACAP occurs through a novel signaling pathway independent from CNTF-JAK/STAT signaling, that is the well-known pathway of astrocytogenesis.

졸른호펜 석회암의 퇴적성인에 대한 점토광물학적 연구 (Clay Mineralogical Study on Genetic Environment of the Solnhofen Limestone)

  • 문지원;박명호;송윤구;문희수
    • 자원환경지질
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    • 제34권3호
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    • pp.243-254
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    • 2001
  • 상부쥐라기 졸른호펜 석회암의 생성환경을 해석하기 위하여 점토광물의 상대함량 변화를 고찰하였다. 전암시료 및 점토입도시료에 대한 광물학적 연구결과에 따르면 포일레층과 플린츠층은 공히 방해석과 석영을 주구성광물로, 소량의 일라이트, 카올리나이트와 스멕타이트를 함유하고 있다. 스멕타이트는 속성작용을 통해 심도에 따라 일라이트화 작용을 심하게 받았으며, 카올리나이트는 심도의 증가에 따라 상대함량이 증가하는 경향을 보인다. 이러한 결과는 다음과 같은 가능성을 제시한다. 즉, 육상기원을 지시하는 카올리나이트 및 석영과 일라이트 등의 쇄설입자의 유입이 상위구간으로 갈수록 감소하고 탄산염광물의 함량이 증가함은 해침을 통해 육성퇴적물의 유입이 감소했음을 의미한다.

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삼황사심탕의 혈관이완 효능과 기전 (Vasodilatory Effects of Samhwangsasim-tang on Vascular Smooth Muscle)

  • 김종봉;권오규;손창우;신흥묵
    • 동의생리병리학회지
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    • 제18권5호
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    • pp.1382-1386
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    • 2004
  • This study was performed for the investigation of vasodilatory efficacy and its underlying mechanisms of Samhwangsasim-tang(SST), herbal remedy. SST relaxed vascular strips precontracted with phenylephrine or KCI(51 mM), but the magnitude of relaxation was greater in phenylephrine(PE) induced contraction. The relaxation effects of SST was endothelium-independent. L-NAME, iNOS inhibitor, and methyl en blue(MB), cGMP inhibitor, did not attenuate the relaxation responses of SST. In the absence of extracellular Ca2+, pre-incubation of the aortic rings with SST significantly reduced the contraction by PE, suggesting that the relaxant action of the SST includes inhibition of Ca/sup 2+/ influx and release of Ca/sup 2+/ from intracellular stores (SR). In addition, the cell death was induced by SST in human aortic smooth muscle cells but not that of human umbilical vein endothelial cells. We conclude that in rat thoracic aorta, SST may induce in part vasodilation through inhibition of Ca/sup 2+/ influx and release of Ca/sup 2+/ from intracellular stores.

Anxiolytic-Like Effects of Cyclopeptide Fraction Alkaloids of Zizyphi Spinosi Semen: Possible Involvement of GABAA Receptors

  • Han, Huishan;Ma, Yuan;Eun, Jae-Soon;Hong, Jin-Tae;Oh, Ki-Wan
    • Biomolecules & Therapeutics
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    • 제16권3호
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    • pp.261-269
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    • 2008
  • This experiment was performed to investigate the anxiolytic-like effects of cyclopeptide fraction alkaloids of Zizyphi Spinosi Semen (CFAZ), by using the experimental paradigms of anxiety, and compared with those of a known anxiolytic, diazepam. CFAZ (8.0 mg/kg, p.o.) increased the percentage of time spent on the open arms and the number of open arms entries in the elevated plus-maze test, increased the number of head dips in the hole-board test, and increased the percentage of center zone ambulatory time in the open-field box. However, CFAZ has no effect on the locomotor activity, while diazepam (2.0 mg/kg, p.o.) significantly reduced locomotor activity. CFAZ did not influence the grip force in the grip strength meter test, either. From the molecular experiments, CFAZ increased chloride influx in cultured cerebellar granule cells. In addition, $GABA_A$ receptors $\gamma$-subunit were over-expressed by CFAZ in cultured cerebellar granule cells. It is concluded that CFAZ may have anxiolytic-like effects, and these effects may be mediated by $GABA_A$ receptors.

휠베어링 고무 실의 접촉력에 관한 연구 (A study on Contact force of Rubber Seal for wheel bearing)

  • 최노진;허영민;이광오;강성수
    • 한국정밀공학회지
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    • 제23권1호
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    • pp.145-151
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    • 2006
  • Wheel bearing unit has been exclusively applied to car wheel supporting device. The seal for wheel bearing is required to have both high sealing effects and low reaction forces because wheel bearing are operated on adverse environmental conditions such as mud and splash water. High sealing effects are for the protection of bearing ball wear from dust influx. In order to ensure high sealing effects, it is a easiest way to increase contact force which are affected by geometric characteristics, material properties and interferences between seal and inner bearing but induces higher wear phenomena. Interferences in all variables are most important factor to determine the performance of wheel bearing. In this study, optimization of interference amount was performed with finite element analysis with commercial code ABAQUS. For the sake of finite element analysis, tensile tests of rubber material were conducted and governing equation of nonlinear behavior was achieved. Hock-up bearing was manufactured with optimized interference amount. Results of torque and mud spray tests using this bearing unit are performed. Less torque and moisture influx of bearing with optimized interference amount is evidence to validity of this study.