• Title/Summary/Keyword: Accumulation ability

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Effect of External Factors on Heavy Metal Accumulation in the Cell of Heavy Metal-Tolerant Microorganisms (중금속내성균의 중금속 축적에 미치는 외부요인의 영향)

  • Cho, Ju-Sik;Lee, Hong-Jae;Lee, Won-Kyu;Heo, Jong-Soo
    • Korean Journal of Environmental Agriculture
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    • v.16 no.2
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    • pp.124-129
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    • 1997
  • This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Heavy metal-tolerant microorganisms, such as Pseudomonas putida, P. aeruginosa, P. chlororaphis and P. stutzeri possessing the ability to accumulate cadmium, lead, zinc and copper, respectively, were isolated from industrial wastewater and mine wastewater polluted with various heavy metals. The effect of several external factors, such as temperature, pH and heavy metal compounds on heavy metal accumulation in the cells was investigated. The amount of heavy metal accumulation into cells according to the kind of heavy metal compound was slightly increased in the case of the heavy metal compound with -nitrate group, but generally, there is little change according to the kind of compound in the amount of heavy metal accumulation. The amount of heavy metal accumulation according to the precultured time was increased in the case of the cell precultured for 24 hours, but generally the precultured time did not affect to the amount of heavy metal accumulation. Heavy metal accumulation into cells was affected by several external factors, such as temperature and pH. The optimum temperature and optimum pH of the accumulation of heavy metal into cells were $20{\sim}37^{\circ}C$ and pH $6{\sim}8$, respectively. By increasing the concentration of each heavy metal-tolerant microorganism in the solution, the total amount of heavy metal accumulated was increased, whereas the amount of heavy metal accumulated per cell(mg, heavy metal/g, dry cells) was decreased. These results indicated that the amount of heavy metal accumulated was not proportional to the concentration of microorganisms.

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Diallel Analysis for Rice Allelopathic Potential against Barnyardgrass Assessed in Field Condition

  • Junaedi, Ahmad;Lee, Sang Bok;Chung, Ill Min;Kim, Kwang Ho
    • Korean Journal of Breeding Science
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    • v.40 no.1
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    • pp.8-14
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    • 2008
  • A complete diallel cross was performed to determine the inheritance of allelopathic potential and combining ability of six rice germplasm that showed different level of allelopathic potential against barnyardgrass. Parents and F1 of 30 crosses were assessed for allelophatic potential in field condition. Barnyardgrass (Echinochloa crus-galli (L.) Beauv. var. frumentaceae) was used for rice allelopathic potential indicator which was observed in height and shoot dry weight, then suppression percentage were calculated by comparing to barnyardgrass grown in control plot (no rice). It was found that general combining ability showed no significant effect, whereas specific combining ability and reciprocal effect were significant. Variance analysis confirmed that genetic control of allelopathic potential in rice against barnyardgrass was mostly directed by dominance gene effect. The dominant genes were associated with high allelopathic potential and recessive genes were associated with low allelopathic potential. Heritability in broad sense for barnyardgrass dry weight suppression was around 41%; whereas for barnyardgrass height suppression was 51%. However, heritability in narrow sense was very low. The finding suggests that accumulation of genes associated with allelopathic potential would be a strategy to develop promising varieties in reference with the specific combining ability of cross combinations.

Non-alcoholic fatty liver protective effects, and studies on the mechanism of action of Crataegi Fructus (산사의 NAFLD 보호 효과 및 그 작용기전에 관한 연구)

  • Kim, Min-Chul;Kong, Ryong;Han, Hyoung-Sun;Kang, Dam-hee;Lee, Seung-Jin;Lee, Cheon-Cheon;Wang, Seo;Kwon, Dong-Yeul;Kang, Ok-Hwa
    • The Korea Journal of Herbology
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    • v.33 no.6
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    • pp.61-70
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    • 2018
  • Objectives : Non-alcoholic fatty liver disease (NAFLD) is characterized by the accumulation of hepatic triglycerides (TG) that leads to inflammation and fibrosis. Crataegi Fructus ethanol extract (CE) is a korean traditional herb that used for digestive diseases. It has been investigated that CE has the effect that prevent hepatotoxicity caused by CCl4 or GaIN and regulate the inflammatory in several organs. However, a hypolipidemic effect of CF has not been reported. Methods : The purpose of this study is that examine the lipid accumulation inhibitory effect of CE on NAFLD. We checked the body and liver weight change of MCD-diet induced mice with/without administration of CE. The blood lipid levels of C57BL/6J mice were checked by biochemistry. Also we observed the liver histology of MCD-diet induced mice and investigate the molecular mechanisms in MCD-diet-induced NAFLD in C57BL/6J mice. Results : CE improved MCD-diet-induced lipid accumulation and TG and TC levels. Also, CE decreased hepatic lipogenesis such as SREBP-1, $C/EBP{\alpha}$, $PPAR{\gamma}$, ACC and FAS. Besides, we also found out that CE increased AMPK phosphorylation. These results indicated that CE has the same ability to activate AMPK and then reduce SREBP-1, and FAS expression, finally leading to inhibit hepatic lipogenesis and hepatic antioxidative ability. Conclusions : In this report, we found CE exerted a regulatory effect on lipid accumulation by decreasing lipogenesis in MCD-diet induced NAFLD model. Therefore, CE extract may be active in the prevention of fatty liver.

Back-Gate Bias Effect of Ultra Thin Film SOI MOSFET's (초 박막 SOI MOSFET's 의 Back-Gate Bias 효과)

  • 이제혁;변문기;임동규;정주용;이진민
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 1999.05a
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    • pp.485-488
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    • 1999
  • In this paper, the effects of back-gate bias on n-channel SOI MOSFETs has been systematically investigated. Back-gate surface is accumulated when negative bias is applied. It is found that the driving current ability of SOI MOSFETs is reduced because the threshold voltage and subthreshold slope are increased and transconductance is decreased due to the hole accumulation in Si body.

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Performance Evaluation for Noise Suppression of a Silencer in Small Arms (소형 화기용 소음기의 소음 저감 성능 평가)

  • 박문선;구태완;강범수
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.9
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    • pp.151-158
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    • 2003
  • The impulse noise of bullet after shooting in small arms has an effect on the hearing ability of human. Although a silencer has been developed for noise reduction in small arms, there is only a few researches about relationships between the sound pressure level and the auditory sense of human. In this study, the quantitative sound pressure levels are revealed by experimental measurements of impulse noise with each silencer type. And the performance evaluation for noise suppression of a silencer in small arms is carried out to reduce a serious loss of the hearing ability of the small arms user. It is concluded that the evaluated results can be utilized for checking sound pressure and data accumulation for new small arms design with silencer.

A Comparative Study on Neural Network Algorithms for Partial Discharge Pattern Recognition (부분방전 패턴인식기법으로서의 Neural Network 알고리즘 비교 분석)

  • Lee, Ho-Keun;Kim, Jeong-Tae
    • Proceedings of the KIEE Conference
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    • 2004.05b
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    • pp.109-112
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    • 2004
  • In this study, the applicability of SOM(Self Organizing Map) algorithm to partial discharge pattern recognition have been investigated. For the purpose, using acquired data from the artificial defects in GIS, SOM algorithm which has some advantages such as data accumulation ability and the degradation trend trace ability was compared with conventionally used BP(Back Propagation) algorithm. As a result, basically BP algorithm was found out to be better than SOM algorithm. Therefore, it is needed to apply SOM algorithm in combination with BP algorithm in order to improve on-site applicability using the advantages of SOM. Also, for the pattern recognition by use of PRPDA(Phase Resolved Partial Discharge Analysis) it is required the normalization of the PRPDA graph. However, in case of the normalization both BP and SOM algorithm have shown worse results, so that it is required further study to solve the problem.

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An Investigation on Migration of Uranium in Soils and Plants in a Phytoremediation System

  • Chang, Pei-chun;Satoshi-Yoshida;Kim, Kyoung-Woong;Kim, Soo-Young
    • Proceedings of the KSEEG Conference
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    • 2003.04a
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    • pp.72-75
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    • 2003
  • Plant species have shown the capability to absorb U into the biomass. Norman(l952) even suggested that uranyl ion acts as an accessory microelement in growth of Lemna and flax roots. The plants, termed metal hyperaccumulators, can extract and accumulate more than 1000-10,000mg heavy metal per kilogram of dry weight of plants (0.1-1%). The most vital main factors influencing the ability and efficiency of phytoremediation is the ability of the plant to uptake the metals from soil before the accumulation mechanism happens in the plant tissue. (omitted)

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Comparative Analysis of BP and SOM for Partial Discharge Pattern Recognition (부분방전 패턴인식에 대한 BP 및 SOM 알고리즘 비교 분석)

  • Lee, Ho-Keun;Kim, Jeong-Tae;Lim, Yoon-Seok;Kim, Ji-Hong;Koo, Ja-Yoon
    • Proceedings of the KIEE Conference
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    • 2004.07c
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    • pp.1930-1932
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    • 2004
  • SOM(Self Organizing Map) algorithm which has some advantages such as data accumulation ability and the degradation trend trace ability was compared with conventionally used BP(Back Propagation) algorithm. For the purpose, partial discharge data were acquired and analysed from the artificial defects in GIS. As a result, basically the pattern recognition rate of BP algorithm was found out to be better than that of SOM algorithm. However, SOM algorithm showed a great on-site-applicability such as ability of suggesting new-pattern-possibility. Therefore, through increasing pattern recognition rate it is possible to apply SOM algorithm to partial discharge analysis. Also, for the image processing method it is required the normalization of the PRPDA graph. However, due to the normalization both BP and SOM algorithm have shown worse results, so that it is required further study to solve the problem.

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Development of Retrofit Method for Beam Using Steel Plate Reinforced by Fiber Sheet (1) (무소음무진동 보보강공법 개발에 관한 연구(1))

  • Kim WooJae;Choi jong moon;Back Sang Tea;Jung SangJin
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.11a
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    • pp.781-784
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    • 2004
  • Method of Steel plate reinforced by fiber sheet is advantageous in the secure loading facility. For this method are a light weight and a high strength, the thickness of steel can be reduced Effects of composite system are depreciated when the thickness of steel is thin. This is the result of the difference of ductility ratio with steel plate. Steel plate reinforced by fiber sheets confirms the ability of transformation. This is the result of the property of steel materials Steel plate reinforced by fiber sheet didn't display an enough performance when theadhesives are epoxy rosin. This is the result of the slide of the surface of stee1. The adhesive ability is varied by the number and span of anchor bolts. There wasn't happening the separation between steel and epoxy. Thus the method used in combination with anchor and epoxy is best excellent. This is the result of the upward of accumulation effects Shearing force is in proportion to the number of bolts. But the ability of shearing force per one bolt is reducing. Thickness of steel plate reinforced by fiber sheet must be designed so that steel is endure before concrete is wreck.

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Lactobacillus plantarum DR7 Reduces Cholesterol via Phosphorylation of AMPK That Down-regulated the mRNA Expression of HMG-CoA Reductase

  • Lew, Lee-Ching;Choi, Sy-Bing;Khoo, Boon-Yin;Sreenivasan, Sasidharan;Ong, Kee-Leong;Liong, Min-Tze
    • Food Science of Animal Resources
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    • v.38 no.2
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    • pp.350-361
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    • 2018
  • Hypercholesterolemia is one of the primary risk factors for cardiovascular diseases. The use of lactobacilli probiotics to reduce blood cholesterol levels have been extensively reported. However, more information is needed to evaluate the possible mechanisms involved and to identify possible targets for further therapeutic development. In this study, strains of lactobacilli were screened based on the ability to assimilate cholesterol, and prevention of cholesterol accumulation in hepatic (HepG2) and intestinal (HT-29) cells. Cell free supernatant (CFS) from Lactobacillus plantarum DR7 showed a higher ability to assimilate cholesterol, reduction in cholesterol accumulation in both HepG2 and HT-29 cells, accompanied by reduced mRNA expression of HMG-CoA reductase (HMGCR) in HepG2 (p<0.05), compared to other lactobacilli. The reduction of HMGCR expression was also diminished in the presence of an AMPK inhibitor (Compound C), suggesting that L. plantarum DR7 exerted its effect via the AMPK pathway, typically via the phosphorylation of AMPK instead of the AMPK mRNA expression in HepG2 (p<0.05). Altogether, our present study illustrated that lactobacilli could exert cholesterol lowering properties along the AMPK pathway, specifically via phosphorylation of AMPK that led to reduced expression of HMGCR.