• Title/Summary/Keyword: time-dependent effect

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Anti-biofilm Activity of Xanthorrhizol Isolated from Curcuma xanthorrhiza Roxb. against Bacterial Biofilms Formed by Saliva and Artificial Multi-species Oral Strains

  • Yanti, Yanti;Rukayadi, Yaya;Lee, Kwan-Hyoung;Han, Sung-Hwa;Hwang, Jae-Kwan
    • Food Science and Biotechnology
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    • v.18 no.2
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    • pp.556-560
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    • 2009
  • Xanthorrhizol, a sesquiterpene isolated from Curcuma xanthorrhiza Roxb., was used to investigate its effect on reducing the saliva and multi-species oral biofilms consisting of Streptococcus mutans, Streptococcus sanguis, and Actinomyces viscosus by anti-biofilm and confocal laser scanning microscopy (CLSM) assays. Xanthorrhizol exhibited significant antibiofilm activity in the dose- and time-dependent manners. Exposure to 2 and $5{\mu}g/mL$ xanthorrhizol for 30 min remained <50% of saliva and multi-species biofilms formed for 24 hr. In addition, exposure to $10{\mu}g/mL$ xanthorrhizol for 30 min reduced 65 and 77% of 24 hr saliva and multi-species oral biofilms, respectively. CLSM results visually demonstrated that xanthorrhizol reduced bacterial viability in the saliva and multi-species oral biofilms. These results suggest that C. xanthorrhiza Roxb. containing xanthorrhizol with strong anti-biofilm activity can be employed as a plant source for oral care functional foods.

The Effect of an Exercise Program on the Physical, Physiological and Emotional Status of the Aged (운동프로그램이 노인의 신체적, 생리적, 정서적 상태에 미치는 영향)

  • Mun, Young-Hee
    • Research in Community and Public Health Nursing
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    • v.17 no.4
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    • pp.451-460
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    • 2006
  • Purpose: The purpose of this research was to examine the effects of an exercise program on the physical, physiological, and emotional status of the aged. Method: This research adopted a nonequivalent control group pretest-posttest design. The subjects were 46 elders aged over 60 who were selected from those registered at three local health centers in G City, and 27 of them were assigned to the experimental group and 19 to the control group. The independent variable was the exercise program, and the dependent variables were physical status, physiological status, and emotional status. The exercise program was Performed for 60 minutes per time, 3 times a week and for 6 weeks. Data were collected from October to November, 2005. Result: Compared to the control group, the experimental group showed significant improvements in right lower extremity strength (F=46.119, p=.000), left lower extremity strength (F=53.265, p=.000) and waist flexibility (t=3.183, p=.003) as physical status, and in depression (t=-3.703, p=.001), perceived health status (t=4.821, p=.000), and self efficacy (t=3.866, p=.000) as emotional status. Conclusion: The results showed that the exercise program was effective in promoting the physical status, physiological status, and emotional status of the aged. Therefore, it is recommended to apply the program as a nursing intervention in clinical practice and education in communities.

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Numerical study of laminar flow and friction characteristics in narrow channels under rolling conditions using MPS method

  • Basit, Muhammad Abdul;Tian, Wenxi;Chen, Ronghua;Qiu, Suizheng;Su, Guanghui
    • Nuclear Engineering and Technology
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    • v.51 no.8
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    • pp.1886-1896
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    • 2019
  • Modern small modular nuclear reactors can be built on a barge in ocean, therefore, their flow characteristics depend upon the ocean motions. In the present research, effect of rolling motion on flow and friction characteristics of laminar flow through vertical and horizontal narrow channels has been studied. A computer code has been developed using MPS method for two-dimensional Navier-Stokes equations with rolling motion force incorporated. Numerical results have been validated with the literature and have been found in good agreement. It has been found that the impact of rolling motions on flow characteristics weakens with increase in flow rate and fluid viscosity. For vertical narrow channels, the time averaged friction coefficient for vertical channels differed from steady friction coefficient. Furthermore, increasing the horizontal distance from rolling pivot enhanced the flow fluctuations but these stayed relatively unaffected by change in vertical distance of channel from the rolling axis. For horizontal narrow channels, the flow fluctuations were found to be sinusoidal in nature and their magnitude was found to be dependent mainly upon gravity fluctuations caused by rolling.

Prediction of Residual Deformation and Stress Distribution for a Thermo-Elastic-Plastic Beam Using a Simplified Numerical Analysis (간이 수치해석에 의한 열탄소성보의 잔류변형 및 응력분포의 예측)

  • S.H. Jun;K. Choi
    • Journal of the Society of Naval Architects of Korea
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    • v.33 no.3
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    • pp.22-34
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    • 1996
  • Regarding the plate bending process by line heating method, in this study a simplified numerical analysis is performed for a beam model to predict its residual deformation and stress distribution. Using the modified strip theory and beam finite element method, a PC-based simulation program is developed for a thermo-elastic-plastic beam. The plate bending problem can be approximately replaced by a beam model using distributed springs to account for the effect of adjacent strips. The spring constants are chosen as the best fit with experiments. In this paper, it is assumed that the temperature distribution is already given and the temperature-dependent material properties are considered. To verify the simulation program, the results using present numerical algorithm are compared with other published experimental results and similar numerical studies. The comparison shows good agreement. The present PC-based computer program also shows good efficiency in computing time.

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Potential Effects of Microglial Activation Induced by Ginsenoside Rg3 in Rat Primary Culture: Enhancement of Type A Macrophage Scavenger Receptor Expression

  • Joo, Seong-Soo;Lee, Do-Ik
    • Archives of Pharmacal Research
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    • v.28 no.10
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    • pp.1164-1169
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    • 2005
  • Brain microglia are phagocytic cells that are the major inflammatory response cells of the central nervous system and widely held to play important pathophysiologic roles in Alzheimer's disease (AD) in both potentially neurotoxic responses and potentially beneficial phagocytic responses. In the study, we examined whether ginsonoside Rg3, a by-product of red ginseng, enhances the microglial phagocytosis of $A{\beta}$. We found that Rg3 promoted $A{\beta}$ uptake, internalization, and digestion. Increased maximal $A{\beta}$ uptake was observed at 4 and 8 h after Rg3 pretreatment (25 ${\mu}g/mL$), and the internalized $A{\beta}$ was almost completely digested from cells within 36 h when pretreated with Rg3 comparing with single non-Rg3-treated groups. The expression of MSRA (type A MSR) was also up-regulated by Rg3 treatment in a dose- and time-dependent manner which was coincidently identified in western blots for MSRA proteins in cytosol. These results indicate that microglial phagocytosis of $A{\beta}$ may be enhanced by Rg3 and the effect of Rg3 on promoting clearance of $A{\beta}$ may be related to the MSRA-associated action of Rg3. Thus, stimulation of the MSRA might contribute to the therapeutic potentials of Rg3 in microglial phagocytosis and digestion in the treatment of AD.

A Research on the core PMO function and operation type for the IT project of financial industry in Korea (금융권 핵심 PMO 기능과 운영형태에 관한 연구)

  • Lee, Jae-Beom;Lee, Jae-Chul;Chang, Yun-Hi
    • Journal of Digital Convergence
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    • v.7 no.3
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    • pp.35-47
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    • 2009
  • The IS project is getting more and more complicated and large-scaled. Many researchers and practitioners are interested in the IS development methodologies, automated tools and techniques, TQM to decrease project failure, and to increase IS performance. But, in spite of such various efforts, the latest Standish Group's research indicates that the project scale is bulkier than $1{\sim}2$ year ago and IS development project's batting average falls from 34% to 28% at the same time, proceeded project is increased, and project discharged arrives to $15%{\sim}18%$. According to a research, success possibility increased by 37% after a year of PMO introduction, and increased sharply by 62% after 2 years and by 65% after S years. This research has a goal to survey how the PMO function and operation type affect the IS project performance in the financial industry. I determine nine independent variables and three dependent variables from previous researches. The results of this study are that the four core functions of PMO have relationship with project performance. But, technical support function does not relate with organization performance. Among the four core PMO operation types, three types have an effect on the IS project performance except the perfectionist type.

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Control of Parturition Time on Pig;IV. Effect of ATP on Uterine Smooth Muscle Motility (돼지 분만 시기의 조절에 관하여;IV. 자궁 평활근의 운동성에 대한 APT의 영향)

  • 박상은;황보원;변유성;조광제
    • Korean Journal of Veterinary Service
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    • v.19 no.2
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    • pp.154-162
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    • 1996
  • The effcets of adenosine 5'-triphosphate(ATP) were investigated on the uterine smooth muscle motility in the pig. The results were summarized as follows: 1. The effects of the porcine uterine smooth muscle and the contractile responses increased between the concentration of ATP $10^{-5}$ and $10^{-3}$ M with a dose-dependent manner. 2. The contractile response induced by ATP($10^{-4}$ M) was not blocked by pretreatment with cholinergic receptor blocker, atropine ($10^{-6}$ M) 3. The contractile response induced by ATP ($10^{-4}$ M) was not blocked by pretreatment with $\alpha$ -adrenergic receptor blocker, phentolamine(10$^{-6}$ M) and ${\beta}$-adrenergic blocker, propranolol ($10^{-6}$ M). 4. The contractile response induced by ATP($10^{-4}$ M) was not appeared in 4Ca^{++}$ -free medium. As the concentration of $Ca^{++}$ in $Ca^{++}$ -free medium was increased, the contractile response induced by ATP ($10^{-4}$ M) was enhenced but was completely inhibited by pretreatment with $Ca^{++}$ -channel blocker, papaverine($10^{-6}$ M) or verapamil($10^{-6}$ M). From these results, it was conclued that the effects of ATP were the contraction mediated by purinergic receptor in uterine smooth muscle of pig.

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Significantly Enhanced Production of Acarbose in Fed-Batch Fermentation with the Addition of S-Adenosylmethionine

  • Sun, Li-Hui;Li, Ming-Gang;Wang, Yuan-Shan;Zheng, Yu-Guo
    • Journal of Microbiology and Biotechnology
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    • v.22 no.6
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    • pp.826-831
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    • 2012
  • Acarbose, a pseudo-oligosaccharide, is widely used clinically in therapies for non-insulin-dependent diabetes. In the present study, S-adenosylmethionine (SAM) was added to selected media in order to investigate its effect on acarbose fermentation by Actinoplanes utahensis ZJB-08196. Acarbose titer was seen to increase markedly when concentrations of SAM were added over a period of time. The effects of glucose and maltose on the production of acarbose were investigated in both batch and fed-batch fermentation. Optimal acarbose production was observed at relatively low glucose levels and high maltose levels. Based on these results, a further fed-batch experiment was designed so as to enhance the production of acarbose. Fed-batch fermentation was carried out at an initial glucose level of 10 g/l and an initial maltose level of 60 g/l. Then, 12 h post inoculation, 100 ${\mu}mol/l$ SAM was added. In addition, 8 g/l of glucose was added every 24 h, and 20 g/l of maltose was added at 96 h. By way of this novel feeding strategy, the maximum titer of acarbose achieved was 6,113 mg/l at 192 h. To our knowledge, the production level of acarbose achieved in this study is the highest ever reported.

Effect of Nisin against Clostridium botulinum During Spore-to-Cell Transformation

  • Chung, Yoon-Kyung;Yousef, Ahmed E.
    • Preventive Nutrition and Food Science
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    • v.12 no.4
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    • pp.259-266
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    • 2007
  • It has been proposed that the mode of action of nisin against vegetative cells and spores of Clostridium botulinum is different. However, clear explanation is not available. Therefore, nisin action against vegetative cells and spores of C. botulinum was investigated in this study. Nisin was added at various stages of spore-to-vegetative cell transition and changes to sensitivity to the bacteriocin were observed. Different nisin preparation (Nisaplin or pure nisin) was compared for their activity against different stages of spore transformation of C. botulinum ATCC 25763. Germination was measured by determining loss of heat resistance and observing phase darkening of spores under phase-contrast microscope. Nisin acted bactericidally against vegetative cells, but acted sporostatically against spores of C. botulinum under the same concentration. This bactericidal and sporostatic action of nisin was dependent on the concentration of nisin used. Presence of nisin during spore activation by heat increased subsequent phase darkening and germination rates. However, nisin inhibited the germination and the outgrowth, when it was added after heat activation stage. Findings from this study suggest that the time of addition of nisin is very important for the effective control of spores during the heating process of foods. In addition, it may be possible to apply nisin at the stage of processing that coincides with the most sensitive stage of spore transformation.

Effect of the Groove Shape of Ultra Thick Box-Column with Center Segregation under High Heat Input for Corner Welding (중심 편석층이 있는 극후판 박스-칼럼의 대입열 코너이음 용접시 그루브 형상의 영향)

  • 최원규;이종봉;권영두;구남서
    • Journal of Ocean Engineering and Technology
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    • v.16 no.2
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    • pp.72-79
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    • 2002
  • In this study, time-dependent distributions of temperature and stresses, in the box-column welded from ultra thick plates with center segregation, has been analyzed by the commercial finite element package SYSWELD+, for several types and angles of groove. The major points of investigation are the optimum type and angle of groove that minimize weld stress specially at the center segregation, as well as temperature distribution, residual stresses and changes in the mechanical properties. The results can be summarized as follows; 1) Generally the thermal cycle at the root of groove exhibits relatively rapid cooling pattern, however, most of the other part weldment have a slow cooling pattern in all groove types. 2) Most of the micro-structures of weldment are composed of ferrite and pearlite, meanwhile we could find martensite and bainite locally a the root of the groove. 3) Optimum groove type for high heat input welding of box-column corner is a double groove type, and the optimum angle for the groove is 30~$45^{\circ}$ that minimize deformation and weld stress at the center segregation.