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        검색결과 18

        1.
        2021.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Colorectal cancer causes the most cancer-associated death worldwide, having a high cancer incidence. Pectin is a complex polysaccharide present in various fruits, emerging as an anti-carcinogenic candidate. Although pectin has a suppressive capacity for colon carcinogenesis, the effect of reactive oxygen species (ROS) generation and colonic aberrant foci formation in the colon carcinogenesis mouse model remains unclear. Therefore, this study investigates the regulatory effect of pectin supplementation on colon carcinogenesis induced by azoxymethane (AOM) and dextran sodium sulfate (DSS) in mice. In an animal experiment, thirty male institute for cancer research (ICR) mice were divided into two experimental groups; AOM/DSS (control group) and AOM/DSS + pectin (5% in drinking water). Furthermore, the number of aberrant crypt foci (ACF) and aberrant crypt (AC) on colonic mucosa were counted, and thiobarbituric acid-reactive substances (TBARS) assay was performed to estimate lipid peroxidation in feces. Pectin treatment significantly decreased the number of ACF and AC per colon compared with the control. Additionally, fecal TBARS level in the pectin group was significantly lower than those in the control group. Conclusively, these findings indicate that pectin-inhibited hyperplastic alteration and oxidative stress suppress colitis-associated colon carcinogenesis.
        4,000원
        7.
        2014.07 구독 인증기관·개인회원 무료
        A choice in temporal discounting is often made on one preferred option between a sooner but smaller reward and a later but larger reward. In temporal discounting, a consumer undergoes an evaluation process concerning the trade-offs between time delay (i.e., a choice between sooner and later receipts) and the amount of reward (i.e., a choice between smaller and larger rewards). It has been evidenced that a surprisingly large number of consumers is inclined to choose a sooner option with a lower economic value. Those consumers tend to apply an excessive temporal discounting rate to the time delay and as a result, the sooner option with lower economic value stands out to be more attractive. However, there is another group of consumers who deliberately promote the long-term perspective in the evaluation process. Those consumers show a high tendency of choosing a later option with greater economic value. A key factor affecting the evaluation process is the sensitivity to time delay a consumer entails. The sensitivity to time delay could systematically affect the representations of hedonic pleasure being projected at different time delays and is the basis of individual differences in hedonic orientation. An anhedonia, a person with the ability to control physical pleasure, is likely to be less sensitive to time delay and apply a lower discounting rate for delayed rewards because he processes the presently available pleasure less intensively than do ordinary consumers. Thus, anhedonic consumers are more likely to choose a delay reward in temporal discounting choices. In a famous fable by Aesop, “The Ant and the Grasshopper” suggest a possible linkage between hedonic orientation and temporal discounting tendency. The story goes that the Grasshopper enjoys whatever is on its hands and does not give much thought to what is going to happen in the future, while the Ant takes on the hardship denying the current pleasure as he plans for the difficult winter time. We conducted an experiment to investigate the relationships among individual differences in hedonic orientation, and the behavioral choices in temporal discounting trials by examining the EEG theta (4-8 Hz) correlates. A hedonic orientation questionnaire was developed using twenty selected items from Physical Anhedonia Scale, Barratt Impulsiveness Scale and Impulsive Buying Scale. Using the questionnaire, the hedonic orientation of fifteen participants was analyzed. Among them, five participants were classified into anhedonia (Ant-like, AN) group and ten participants were into hedonic pleasure dependent (Grasshopper-like, GH) group. Participants conducted ten temporal discounting trials and, in each trial, a choice was made between two options, either a smaller reward today (the “now” option) or a greater reward to be received after a specified time delay (the “future-oriented” option). The absolute theta activations while viewing a future-oriented option in each trial were analyzed as the neural correlates of temporal discounting. The results indicated that the hedonic orientation of participants had a high prediction power of not only behavioral choices in temporal discounting but also EEG theta activations in the frontal brain region. In analyzing temporal discounting tendencies, the discounting rate of AN group was found to be lower than that of GH group. In addition, EEG theta analysis shows two interesting activation patterns in the frontal region. First, AN group showed higher frontal theta activations than GH group indicating its deliberate engagement to future-oriented options. Second, theta activations in the Dorsolateral Prefrontal Cortex (DLPFC), more specifically AF3 and AFz, were negatively correlated with the discounting rate of participants. Neuroscience researches often refer that DLPFC is associated with deliberate and analytic information processing. Therefore, the high theta activations in DLPFC could be considered as a distinctive neural indicator of high anhedonia traits and low temporal impulsivity.
        8.
        2014.07 구독 인증기관·개인회원 무료
        The aim of the present research is to explore the neural features of intertemporal choice. Intertemporal choice concerns the phenomenon of temporal discounting which demonstrates consumers’ tendency to devalue a future reward as the receipt of money reward is delayed further distantly into the future. It is also called the ‘present bias,’ a special kind of attachment consumers place to immediate a cash reward which consumers are willing to take even at a discount, instead of saving it for the future. The urge to choose an immediate reward at some discounting rates, i.e., temporal impulsivity, is deeply embedded in our instinct. On the other hand, the choice for a delayed option is made as a result of effortful and deliberate cognitive control, by suppressing the urge for instant gratification and shifting focus to the long-term gain. Neuroscience researchers have found the prefrontal cortex as a key brain region behind deliberate and analytic decision-making such as reward delay. The experimental paradigm used in this study adopted from Kirby, Petry, & Bickel (1999). There were ten intertemporal investment choices representing six different levels of discounting rates. Participants (N=21) were given the two investment options, as “take it now” and a “save for later” options, and they were asked to indicate a preferred option. The brain waves were recorded using a 32 channel EEG system. We conducted noise control by using Independent Component Analysis (ICA) in EEGLAB and analyzed the Event-Related Potentials (ERP) particularly focusing on the phase when each participant was examining the future-oriented “save for later” option. The behavioral responses were divided into two groups, one in which the present option was selected and the other in which a future-oriented “save it for later” option was selected. Custom-written Matlab codes were used to compare the differences in ERPs between the two choice responses. A greater positive component of P3 after 300 milliseconds at the onset of the future option was observed in the fronto-parietal regions when the “save it for later” options were chosen compared to when the “take it now” choices were made. Hence, during intertemporal choice, the fronto-parietal regions are likely to play a key role in enabling the long-term perspective and consequently, precipitate the choice of a future-oriented deal. The P3 signal across the fronto-parietal regions may potentially be a proximal indicator of a future-oriented choice during intertemporal financial decision-making.
        9.
        2013.04 구독 인증기관·개인회원 무료
        Emergence of resistant two-spotted spider mite (TSSM) can induce the over usage of standard amount of acaricides and result in various side effects. Rapid resistance monitoring is essential step for the efficient management of resistant populations by enabling the selection of appropriate acaricides. Here, we evaluated the 10 acaricides to determine its suitability on residual contact vial bioassay (RCV) by using PyriF strain as standard. Five acaricides (Abamectin, monocrotophos, tebufenpyrad, bifenazate and cyflumetofen) revealed the dose-dependent mortality within 8 h, whereas other remaining acaricides (Fenbutatin oxide, fenpyroxymate, flufenoxuron, spiromesifen and etoxazole) did not. This finding suggests that the application of RCV method is limited depending on the mode of action and physicochemical properties of each acaricide. Resistance levels to five acaricides (Abamectin, monocrotophos, tebufenpyrad, bifenazate and cyflumetofen) were determined for four field populations of TSSM by using RCV diagnostic kit. All TSSM populations showed the highest sensitivity to cyflumetofen, indicating that it would be most effective in controling field populations. RCV diagnostic kit would enable to provide crucial information for choosing the most appropriate acaricides in the field.
        10.
        2011.03 구독 인증기관 무료, 개인회원 유료
        The faulty regulation of imprinting gene lead to the abnormal development of reconstructed embryo after nuclear transfer. However, the correlation between the imprinting status of donor cell and preimplantation stage of embryo development is not yet clear. In this study, to determine this correlation, we used the porcine spermatogonial stem cell (pSSC) and fetal fibroblast (pFF) as donor cells. As the results, the isolated cells with laminin matrix selection strongly expressed the GFRα-1 and PLZF genes of SSCs specific markers. The pSSCs were maintained to 12 passages and positive for the pluripotent marker including OCT4, SSEA1 and NANOG. The methylation analysis of H19 DMR of pSSCs revealed that the zinc finger protein binding sites CTCF3 of H19 DMRs displayed an androgenic imprinting pattern (92.7%). Also, to investigate the reprogramming potential of pSSCs as donor cell, we compared the development rate and methylation status of H19 gene between the reconstructed embryos from pFF and pSSC. This result showed no significant differences of the development rate between the pFFs (11.2±0.8%) and SSCs (13.3±1.1%). However, interestingly, while the CTCF3 methylation status of pFF-NT blastocyst was decreased (36.3%), and the CTCF3 methylation status of pSSC-NT blastocyst was maintained. Therefore, this result suggested that the genomic imprinting status of pSSCs is more effective than that of normal somatic cells for the normal development because the maintenance of imprinting pattern is very important in early embryo stage.
        4,000원
        11.
        2010.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study aims to reveal how EA affects BAX and NF-kB involved in cell deaths from global ischemia, and to do this, observes the changes of BAX and NF-kB caused by EA application after transient global ischemia. The experimental method is to give rise to global ischemia and apply EA to 27 SD rats with the particulars of being six-week-old, male, around-300 gram-weighing, and adapted to laboratory environment for more than a week, and divide them into three groups, that is, GV20 EA group(n=9), L14 EA group(n=9), no-treatment GI group(n=9), and then observe their changes of BAX and NF-kB at the time lapse of 6 hours, 9 hours and 12 hours after ischemia, using western blotting. The numerical decrease of BAX expression at the time lapse of 9 hours after EA application, though not statistically significant, was observed in GV20 EA group and L14 EA group, and the NF-kB expression appeared statistically significant decrease in GV20 EA group and L14 EA group, but the expression was higher in the group with EA application. Therefore, EA application at the early phase of global ischemia is considered to affect BAX and NF-kB and play a positive role in decreasing apoptosis and cell deaths by inflammation.
        4,000원
        12.
        2009.12 구독 인증기관 무료, 개인회원 유료
        The Mental Image is designed and proposed for making a comfort and amenity in built environments using digital color analysis in the regional urban artificial environment. For a long time, it is crucial to relate visual environment with thermal environments. Especially, color makes an important role to making thermal comfort. In order to making this information, this paper describes how we can analyze the color information of the regional urban artificial environment using the color syntax program and transfer the data to form maker and create the mental image. Because of the rapid urbanization and the acceptance of mixed function, modern urban landscape is disordered and is not controlled. The Mental Image prepares our environmental color system corresponding to our mental image with perceiving regional urban environment color. This research aims to systematize the process making the Mental Image in the regional urban landscape’s color and suggest a theoretical basis to extract, embody and use the information of the regional main color from urban landscape color. Through these concepts, this research will suggest how to systematize, develop the Mental Image with emotional environmental color system. Finally, it is expected to offer a theoretical basis to embody the Mental Image and build up the emotional environments.
        4,000원
        17.
        2006.08 KCI 등재 서비스 종료(열람 제한)
        A new oat (Avena sativa L.) cultivar 'Darkhorse' was developed by Honam Agricultural Research Institute (HARI) m2005. It was released because ofits earlmess, high forage yield potential and adaptability for late summer sowing. It was devel-oped from the a
        18.
        2006.08 KCI 등재 서비스 종료(열람 제한)
        A new oat (Avena sativa L.) cultivar, "Highspeed" was developed by Honam Agricultural Research Institute (HARI) in2005. It was released because of its earliness, high forage yield potential, and good adaptability for late summer sowing. "High-speed" was s