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        검색결과 78

        42.
        2007.04 KCI 등재 구독 인증기관·개인회원 무료
        Al t hough substance P(SP) , a potent pro- inflammatory peptide, is involved in inflammation and immune responses‘ t he eff'ect of SP on t he expression of macrophage inflammatory protein 3a (MIP- 3α CCL20) in periodontal liga ment(PDL) cell s a re unknown, Equally as enigmatic is the link between SP, t he stress protein heme oxygenase- l(HO-l) ‘ and CCL20 procluction, We investigated whether SP induces the release of chemokine CCL20 from immortal ized PDL(IPDL) ceJJ s‘ and fur ther c l a꺼 SP mediated pathways, We also examined the relationship between HO-l a ncl CCL20 by t reating PDL cells with SP, Incubating IPDL cells with SP increased expression of CCL20 mRNA a nd CCL20 protein in a dose-time dependent manner Highly selective p38 and ERKl/2 inhibitors abrogated SP-induced expression of CCL20 in IPDL cell s, SP is a lso responsible for ini t iating phosphorylation of I/C B, degradation of Iκ B‘ ancl activat ion of NF'-/C B, SP induced expression of HO-l in both a concentration- and time-dependent man nel ‘ and CCL20 refl ected s imilar patterns, The inductive effects o[ SP on HO- l and CCL20 wer e enhanced by HO- j inducer hemin and the membrane-permeable cGMP analog 8-bromo-cGMP, Conversely, this pathway was inJübited by t he 1-10난 inhi bitor zinc protoporphyrin IX(ZnPP IX) and the selective inl뼈itor of guanylate cyc1ase‘ lH-[l , 2, 4Joxad iazole[4‘ 3-aJquinoxal in-l-one (ODQ) , We report herein the pathway that connects SP along with other modulators 。f neuroimmunoregulationto the induction of HO-l and t he inflammatory mediator MIP-3a /CCL20 in IPDL cell s‘ which play an important role in the development 01' periodontitis or inflamrnation during orthodontic tooth movem
        44.
        2004.12 구독 인증기관 무료, 개인회원 유료
        Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo. Human ES cells have the capacity to differentiate into various types of cells in the body. Human ES cells are indefinite source of cells for cell therapy in various degenerative disorders including neuronal disorders. Directed differentiation of human ES cells is a prerequisite for their clinical application. The objective of this study is to develop the culture condition for the derivation of neural precursor cells from human ES cells. Neural precursor cells were derived from human ES cells in a stepwise culture condition. Neural precursor cells in the form of neural rosette structures developed into neurospheres when cultured in suspension. Suspension culture of neurospheres has been maintained over 4 months. Expressions of nestin, soxl, sox2, pax3 and pax6 transcripts were upregulated during differentiation into neural precursor cells by RT-PCR analysis. In contrast, expression of oct4 was dramatically downregulated in neural precursor cells. Immunocytochemical analyses of neural precursor cells demonstrated expression of nestin and SOX1. When induced to differentiate on an adhesive substrate, neuro-spheres were able to differentiate into three lineages of neural systems, including neurons, astrocytes and oligo-dendrocytes. Transcripts of sox1 and pax6 were downregulated during differentiation of neural precursor cells into neurons. In contrast, expression of map2ab was elevated in the differentiated cells, relative to those in neural precursor cells. Neurons derived from neural precursor cells expressed NCAM, Tuj1, MAP2ab, NeuN and NF200 in immunocytochemical analyses. Presence of astrocytes was confirmed by expression of GFAP immuno-cytochemically. Oligodendrocytes were also observed by positive immuno-reactivities against oligodendrocyte marker O1. Results of this study demonstrate that a stepwise culture condition is developed for the derivation of neural precursor cells from human ES cells.
        4,000원
        46.
        1998.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Korea is located in either low of moderate seismicity continental region. It is realized that the design codes and underlying design concept of high seismicity region may not be a, pp.opriate to low and moderate seismicity regions. The aim of this paper is to search seismic design concept that is deemed to be a, pp.opriate to low and moderate seismicity regions. To this end, the seismicity of Korea will be introduce first and important aspects of seismic design in moderate seismicity region will be discussed. The two-level code system that is going to be adopted in the future seismic regulations of Korea will be introduced.
        4,200원
        47.
        2018.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구는 완주에서 재배된 세계 주요 11개 적포도 품종으로 제조된 적포도주의 향기 성분을 headspace-solid phase microextraction 분석법으로 확인하였다. 향기성분은 총 75종이 확인되었다. 아로마화합물은 그들의 OAV 값에 의해 5 그룹으로 나뉘었다. 알콜, 알데하이드, 에스테르, C6 화합물이 11개 적포도주의 주요한 향기성분이었다. Isoamy alcohol 알콜과 phenylethyl 알콜은 11개 포도주에서 공통적으로 꽃향기, 달콤한 향을 나타내는데 중요한 물질이었다. Octanoic acid, ethyl ester, hexanoic acid ethylester은 모든 레드와인에서 과실향과 꽃향, 달콤한 향을 내는 중요한 성분이었다. 1-Hexanol은 모든 포도주에서 분석되었으나 풀향을 나타내는 향으로 나타났다. Chanceller, Malbec, marchel, Nsrsha, Pinot Meunier, Sangiovetto 포도주의 주요 향기성분은 과실 향인 것으로 나타났으며 Cabernet Franc, Cabernet Sauvignon, Sauvignon Vert 포도주의 주요 향기성분은 풀향인 것으로 조사되었다. 또한, MBA와 Narsha 포도주의 경우 꽃향이 주요 향인 것으로 조사되었다. 본 연구 결과를 바탕으로 적포도주용 품종을 육성할 때 선발기준으로 향기성분 분석을 활용할 수 있을 것으로 판단되었다.
        48.
        2018.04 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The study compared the juice and wine odorants of the Cheongsoo grape cultivar with those of Chardonnay and Reisling wines. The volatile compounds of the three grape varieties were analyzed using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry. The most common volatile compounds in the juices from the three cultivars were terpenes, C13-norisoprenoids, etones, alcohols, and aldehydes. Terpenes were established as the most abundant group of volatiles in Cheongsoo grape juice, where as aldehydes predominated in Chardonnay and Riesling juices. Forty-two volatile compounds (acids, alcohols, esters, and others) were detected in the three white wines. The concentration of esters was about four times higher in Cheongsoo wine than in Chardonnay and Riesling wines. Five esters found in the Cheongsoo wine, namely, isoamyl acetate, ethyl butanoate, ethyl hexanoate, ethyl octanoate, and ethyl decanoate, exhibited high odor activity values (OAV) of >1. Furthermore, only Cheongsoo wine had a high OAV for isoamyl acetate odorant, which is associated with banana and sweet aromas. Therefore, the abundant and varied esters are believed to be key volatile fruity/sweet odorants in Cheongsoo wine.
        49.
        2017.11 서비스 종료(열람 제한)
        There is a rising interest of depletion of deposited fossil fuel and environmental pollution, inducing extensive studies to find new alternative sustainable energy sources to replace current petroleum based energy usage. As one of solutions, anaerobic digestion (AD) treating organic wastes has been considered one of the most promising processes owing to its sustainability, low production of sludge, unnecessariness of aeration, and biogas generation. Swine wastewater is characterized by high strength of organic matter contents, so it is regarded as a potential feedstock to produce methane through AD process. To investigate the functional relationship between the microbial communities and anaerobic process performance, regular seasonal sampling was done at four full scale anaerobic digesters treating swine wastewater in South Korea for two years. As results of process and microbial community analyses, chemical oxygen demand (COD) removal efficiency was monitored to proportional to those of carbohydrates, proteins and lipids. Methanogenic and bacterial populations were also positively related to the removal efficiencies of carbohydrates and lipids. However, proteins removal efficiency was independent of microbial population. It means that microbial communities in full scale anaerobic digesters are most likely to be mainly associated with carbohydrates and/or lipids metabolisms, indicating that proteins may be putative recalcitrant contents in wastewater. The microbial population tends to be more affected by places rather than seasons; however, with respect to seasons, the highest species abundances were observed mainly at winter. This implied that rising temperature in the anaerobic digesters in summer would be not suitable for the growth of mesophilic microorganisms, known to be predominant in anaerobic process. Actually, this speculation is supported by the fact that the highest removal efficiency of COD was measured at winter samples. The marked information in this study must provide a real insight into the effective field operation of anaerobic digestion.
        50.
        2016.10 서비스 종료(열람 제한)
        Background : Despite the presence of various bioactive compounds in ginseng, there is lack of study on the variations of bioactive compounds in ginseng according to the cultivation of soil and the applied fertilizer types (or amount). Therefore, this study aims to examine the variations of 37 fatty acids (FA) and 8 vitamin E (Vit-E) vitamers in 6-year-old ginseng root cultivated in different soil types with different fertilizers regimes. Methods and Results : The profiling of 37 FAs and 8 Vit-E vitamers in 6-year-old ginseng roots was measured by gas chromatography coupled with a flame ionization detector, and then these results were statistically analyzed with chemometrics. The FA and Vit-E content in ginseng roots varied significantly with respect to soil cultivation conditions due to organic fertilizer types and amounts used. Unsaturated FA in ginseng is approximately 2.7 fold higher than the saturated FA. Linoleic, palmitic, and oleic acids were the most abundant FAs found in the ginseng roots. Also, the major Vit-E vitamer found in ginseng root is α -tocopherol. In particular, the application of rice straw compost or food waste fertilizer was increased to create nutritionally-desirable FAs and bioactive Vit-E in ginseng root. In addition, phytonutrient profiling coupled with chemometrics can be used to discriminate the cultivation conditions of ginseng. Conclusion : This preliminary study extends our understanding about the variations of FA and Vit-E in ginseng root depending on cultivation conditions. Hence, these results can be useful as basic information for reliable ginseng production containing high amounts of phytonutrients in a paddy-converted field.
        51.
        2016.10 서비스 종료(열람 제한)
        Background : Some of invasive plants, which were introduced from foreign countries, have caused problems in Korea. Invasion of these invasive plants in the ecosystem threatens the habitat of endemic species, reducing biodiversity, and causing a disturbance in the ecological system. Hypochaeris radicata L. (Asteraceae), the most invasive plants in Korea, particularly in Jeju Island, invade farmland, and autochthonous forest, establishing monocultures and modifying the ecosystem structure. This invasive species has become a serious environmental problem because they displace the indigenous plant species. This study was conducted to evaluate the antioxidantive effects of ethanolic extracts from different parts (root, stem, seed and leaf) of the invasive exotic species Hypochaeris radicata L. Methods and Results : The aim of present study was to estimate the total phenolic and flavonoid contents and to investigate in vitro antioxidant potential of ethanolic leaf, root, seed, and stem extracts of the Hypochaeris radicata. Antioxidant activity was assessed by using 2,2-diphenyl-1-picryl-hydrazyl (DPPH) assay, reducing power activity, [2,2-azino-bis(3-ethylbenzthiazoline-6-sulphonic acid)] ABTS+ assay and ferrous ion chelating activity. The total phenolic and flavonoid contents were also determined and expressed in gallic acid and quercetin equivalent respectively. The results of the study indicate that the ethanolic extracts of the leaf, root, seed, and stem of H. radicata posses significant scavenging activity against DPPH (21.25% for leaf, 34.98% for root, 60.76% for seed and 45.25% for stem at 250 μg/ml each) and ABTS+ radical scavenging activity (14.85% for leaf, 17.40% for root, 35.91% for seed and 24.70% for stem at 250 μg/ml each), reducing power activity (0.178 absorbance at 300 μg/ml for leaf, 0.211 absorbance at 300 μg/ml for root, 0.447 absorbance at 300 μg/ml for seed, 0.276 absorbance at 300 μg/ml for stem). The free radical scavenging and antioxidant activities may be attributed to the presence of adequate phenolic (gallic acid content is 361.92.98 μg/g in leaf, 356.59μg/g in root, 719.72 μg/g in seed and 512.08 μg/g stem) and flavonoid compounds (219.52 μg/g in leaf, 75.67μg/g in root, 281.39 μg/g in seed and 215.66 μg/g stem). This study revealed that the ethanolic extracts of both leaf, root, seed and stem of H. radicata has demonstrated significant antioxidant activity. Conclusion : In conclusion, the present study has demonstrated that Hypochaeris radicata seed ethanol extracts are rich in phenolics and have a strong antioxidant activity and a radical-scavenging action in all of the tested methods. This suggests that Hypochaeris radicata is a good source of natural antioxidants.
        52.
        2016.10 서비스 종료(열람 제한)
        Background : More than 1250 bamboo species, belonging to 75 genera, are distributed all over the world. Sasa quelpaertensis Nakai is a type of bamboo grass widely distributed in Halla mountain, Jeju Island, which has been used as antidiabetic, anti-cancer and anti-inflammatory drugs. In this study, we investigated the antioxidant and antimicrobial activities of Sasa quelpaertensis Nakai leaf extracted with different ethanol concentration and demonstrated the potent bioactivities of the extracts suitable to be used as natural antioxidant compounds or pharmaceutical supplements. Methods and Results : Antioxidant and anti-microbial activities of Sasa quelpaertensis Nakai extracts were studied. At first, different ethanol concentrations (0, 20, 40, 60 and 80%) were compared for determining of the best solvent for extraction of phenolic compounds from Sasa quelpaertensis Nakai. Forty percent Ethanol extract with 990.01±28.9 (mg of gallic acid equivalents/g sample) were the best solvent in the extraction of phenolic compounds. But, 60% ethanolic extracts were highest antioxidant activity appeared such as DPPH radical scavenging (IC50 21.20±0.42 μg/ml), ABTS radical scavenging (IC50 49.85±1.27 μg/ml) and reducing power. However, 80% ethanol extracts showed the strongest SOD like activity. The anti-microbial capacity was screened against Gram positive and Gram negative bacteria, and yeast. Sixty percent and 80% ethanol extracts inhibited the growth of Gram positive bacteria; Bacillus cereus was the most susceptible one with MIC of 125 μ g/ml and 250 μg/ml for the 60% and 80% extracts, respectively. Conclusion : The results of this study show that the extract of Sasa quelpaertensis Nakai can be used as easily accessible source of natural antioxidants and as a possible food supplement or in pharmaceutical industry. However, the components responsible for the antioxidant and antimicrobial activities of both extracts of Sasa quelpaertensis Nakai are currently unclear. Therefore, it is suggested that further works should be performed on the isolation and identification of the antioxidant components in Sasa quelpaertensis Nakai.
        53.
        2016.09 KCI 등재 서비스 종료(열람 제한)
        The optimum concentrations of clove oil as an anesthetic for olive flounder (Paralichthys olivaceus) and the stress response of the fish to clove oil anesthesia were determined over a range of water temperatures, and investigated in a simulated transport experiment using analysis of various water and physiological parameters. While the time for induction of anesthesia decreased significantly as both the concentration of clove oil and water temperature increased, the recovery time increased significantly (P<0.05). The plasma cortisol concentration in fish at each temperature increased significantly up to 12 h following exposure (P<0.05), then decreased to 48 h (P<0.05). The DO dissolved oxygen concentrations, pH values, and the fish respiratory frequencies decreased over 6 h following exposure to clove oil in all experimental groups (P<0.05), whereas the NH4 + and CO2concentrations in all experimental groups increased up to 6 h (P<0.05). The pH values and DO concentrations increased with increasing clove oil concentration (P<0.05) in the 6 h following exposure, and the CO2 and NH4 + concentrations and the respiratory frequencies decreased with increasing clove oil concentration (P<0.05). The results of this experiment suggest that clove oil reduced the metabolic activity of olive flounder, thus reducing NH4 + excretion and O2 consumption. In conclusion, clove oil appears to be a cost-effective and efficient anesthetic that is safe for use and non-toxic to the fish and users. Its use provides the potential for improved transportation of olive flounder.
        54.
        2015.07 서비스 종료(열람 제한)
        To understand molecular mechanisms underlying adaptation of plant cells to saline stress and stress memory, we developed Arabidopsis callus suspension-cultured cells adapted to high salt. Adapted cells to high salt exhibited enhanced tolerance compared to control cells. Moreover, the salt tolerance of adapted cells was stably maintained even after the stress is relieved, indicating that the salt tolerance of adapted cells was memorized. Salt-adapted and stress memorized cells were densely aggregated and formed multi-layered cell lump. Cell morphology analysis using transmission electron microscopy indicated that cell wall thickness of salt-adapted cells was significantly induced compared to control cells. In order to characterize metabolic responses of plant cells during adaptation to high salt stress as well as stress memory, we compared metabolic profiles of salt-adapted and stress-memorized cells with control cells by using NMR spectroscopy. A principle component analysis showed clear metabolic discrimination among control, salt-adapted and stress-memorized cells. Compared with control cells, metabolites related to shikimate metabolism such as tyrosine, and flavonol glycosides, which are related to protective mechanism of plant against stresses were largely up-regulated in adapted cell lines. Moreover, coniferin, a precursor of lignin, was more abundant in salt-adapted cells than control cells. The results provide new insight into metabolic level mechanisms of plant adaptation to saline stress as well as stress memory.
        55.
        2015.07 서비스 종료(열람 제한)
        To identify novel signaling components involved in regulation of plant responses to phosphate (Pi) starvation, we screened an Arabidopsis T-DNA activation tagging library for mutants with altered Pi-starvation responses. Here, we report the identification and characterization of novel activation-tagged mutant involved in Pi starvation signaling in Arabidopsis. The hpd (hypersensitive to Pi deficiency) mutant exhibits enhanced phosphate uptake and altered root architectural change under Pi starvation compared to wild type. Expression analysis of auxin-responsive DR5::GUS reporter gene in hpd mutant indicated that both auxin biosynthesis and auxin translocation under Pi starvation are suppressed in hpd mutant plants. Impaired auxin translocation in roots of hpd mutant was attributable to abnormal root architecture changes in Pi starvation conditions. Mis-regulation of auxin translocation in hpd mutant was further confirmed by analysis of expression patterns of auxin efflux carrier proteins, PIN-FORMED (PIN) 1, 2, and 3 fused with GFP. Not only expression levels but also expression domains of PIN proteins were altered in hpd mutant in response to Pi starvation. Molecular genetic analysis of hpd mutant revealed that the mutant phenotype is caused by the lesion in ENHANCED SILENCING PHENOTYPE4 (ESP4) gene whose function is proposed in mRNA 3’-end processing. The results propose that mRNA processing plays crucial roles in Pi homeostasis as well as developmental reprograming in response to Pi deprivation in Arabidopsis.
        56.
        2012.12 KCI 등재 서비스 종료(열람 제한)
        To achieve a differential advantage over competitors and protect their long-term interest, shipping lines have striven to find ways to maintain an ongoing relationship with shippers which can be achieved by attaining their loyalty. The benefits of loyal shippers are potentially huge in that they generate long-term revenue streams as well as provide cost savings as compared with attracting new shippers. Logistics service provided by shipping lines is identified as one of the effective tools for building customer loyalty. However, in a review of the literature none of the studies examine how logistics service creates customer loyalty, particularly between shipping lines and shippers. Consequently, the overarching purpose of this paper is to extend knowledge on logistics service performance and its relationship with customer loyalty in the unique context of maritime transport by proposing a new conceptual model based on an extensive literature review. The major contribution is to offer a new insight into the complex relationships between those 'soft' concepts in the context of maritime transport.
        57.
        2012.07 서비스 종료(열람 제한)
        Phosphorus is one of the macronutrients essential for plant growth and development, as well as crop productivity. Many soils around the world are deficient in phosphate (Pi) that plants can utilize. To cope with the stress of Pi starvation, plants have evolved many adaptive strategies, such as changes of root architecture and enhanced Pi acquisition form soil. To understand molecular mechanism underlying Pi starvation stress signaling, we characterized the activation-tagged mutant showing altered responses to Pi deficiency compared to wild type Arabidopsis and named hsp3 (hypersensitive to Pi starvation3). hsp3 mutant exhibits enhanced phosphate transporter activity, resulting in higher Pi content than wild type. However, in root architectural change under Pi starvation, hsp3 shows hyposensitive responses than wild type, such as longer primary root elongation, lower lateral root density. Histochemical analysis using hsp3 mutant expressing auxin-responsive DR5::GUS reporter gene, indicated that auxin allocation from primary to lateral roots under Pi starvation is aborted in hsp3 mutant. Molecular genetic analysis of hsp3 mutant revealed that the mutant phenotype is caused by the lesion in ENHANCED SILENCING PHENOTYPE4 (ESP4) gene whose function is proposed in mRNA 3’ end processing. Here, we propose that mRNA processing plays a crucial role in Pi homeostasis in Arabidopsis.
        58.
        2012.07 서비스 종료(열람 제한)
        In order to adapt to various environmental stresses, plants have employed diverse regulatory mechanisms of gene expression. Epigenetic changes, such as DNA methylation and histone modifications play an important role in gene expression regulation under stress condition. It has been known that some of epigenetic modifications are stably inherited after mitotic and meiotic cell divisions, which is known as stress memory. To understand molecular mechanisms underlying stress memory mediated by epigenetic modifications, we developed Arabidopsis suspension-cultured cell lines adapted to high salt by stepwise increases in the NaCl concentration up to 120 mM. Adapted cell line to 120 mM NaCl, named A120, exhibited enhanced salt tolerance compared to unadapted control cells (A0). Moreover, the salt tolerance of A120 cell line was stably maintained even in the absence of added NaCl, indicating that the salt tolerance of A120 cell line was memorized even after the stress is relieved. By using salt adapted and stress memorized cell lines, we intend to analyze the changes of DNA methylation, histone modification, transcriptome, and proteome to understand molecular mechanisms underlying stress adaptation as well as stress memory in plants.
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