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        검색결과 173

        21.
        2020.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        After nuclear power plants are permanently shut down and decommissioned, the remaining irradiated metal components such as stainless steel, carbon steel, and Inconel can be used as neutron absorber. This study investigates the possibility of reusing these metal components as neutron absorber materials, that is burnable poison. The absorption cross section of the irradiated metals did not lose their chemical properties and performance even if they were irradiated over 40-50 years in the NPPs. To examine the absorption capability of the waste metals, the lattice calculations of WH 17×17 fuel assembly were analyzed. From the results, Inconel-718 significantly hold-down fuel assembly excess reactivity compared to stainless steel 304 and carbon steel because Inconel-718 contains a small amount of boron nuclide. From the results, a 20wt% impurity of boron in irradiated Inconel-718 enhances the excess reactivity suppression. The application of irradiated Inconel-718 as a burnable absorber for SMR core was investigated. The irradiated Inconel-718 impurity with 20wt% of boron content can maintain and suppress the whole core reactivity. We emphasize that the irradiated metal components can be used as burnable absorber materials to control the reactivity of commercial reactor power and small modular reactors.
        4,900원
        22.
        2020.11 구독 인증기관 무료, 개인회원 유료
        This research scrutinizes the synergism of virtual reality, the Internet, and television on credibility, memory, attitude, presence, and purchase intention. Respondents are randomly assigned to view two advertisements on the same or different media. This present study parses outs the relationship between immersive media and extant media in cross-media advertising.
        3,000원
        23.
        2020.09 구독 인증기관 무료, 개인회원 유료
        Acacetin, which is present in damiana (Turnera diffusa ) and black locust (Robinia pseudoacacia ), has several pharmacologic activities such as antioxidant, anti-inflammatory, and anti-proliferative effects on cancer cells. However, the effect of acacetin on head and neck cancers has not been clearly established. This study aimed to examine the effects of acacetin on cell growth and apoptosis induction in FaDu human pharyngeal carcinoma cells. These were investigated by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay, Live/Dead cell assay, 4′,6-diamidino-2-phenylindole dihydrochloride staining, caspase-3 and caspase-7 activation assay, and immunoblotting in FaDu cells. Acacetin induced FaDu cell death in a dose-dependent manner, with an estimated IC50 value of 41.9 µM, without affecting the viability of L-929 mouse fibroblasts as normal cells. Acacetin treatment resulted in nuclear condensation in the FaDu cells. It promoted the proteolytic cleavage of procaspase-3, -7, -8, and -9 with increasing amounts of the cleaved caspase isoforms in FaDu cells. Acacetin-induced apoptosis in FaDu cells was mediated by the expression of Fas and activation of caspase-8, caspase-3, and poly (ADP-ribose) polymerase. Immunoblotting showed downregulation of the anti-apoptotic mitochondrial proteins Bcl-2 and Bcl-xL, but upregulation of the mitochondria-dependent pro-apoptotic proteins Bax and Badin FaDu cells after acacetin treatment. These findings indicate that acacetin inhibits cell proliferation and induces apoptotic cell death in FaDu human pharyngeal carcinoma cells via both the death receptor-mediated extrinsic apoptotic pathway and the mitochondria-mediated intrinsic apoptotic pathway.
        4,000원
        24.
        2020.09 구독 인증기관 무료, 개인회원 유료
        Ficus carica L. (fig ) is one of the first cultivated crops and is as old as humans. This plant has been extensively used as a traditional medicine for treating diseases, such as cough, indigestion, nutritional anemia, and tuberculosis. However, the physiological activity of fig leaves on oral cancer is as yet unknown. In this study, we investigated the anticancer effect of methanol extracts of Ficus carica (MeFC) and the mechanism of cell death in human FaDu hypopharyngeal squamous carcinoma cells. MeFC decreased the viability of oral cancer (FaDu) cells but did not affect the viability of normal (L929) cells, as determined by 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay and Live and Dead assay. In addition, MeFC induced apoptosis through the proteolytic cleavage of procaspase-3, -9, poly (ADP-ribose) polymerase (PARP), downregulation of Bcl-2, and upregulation of Bax, as determined by 4′,6-diamidino-2-phenylindole dihydrochloride staining and western blot analysis. Moreover, a concentration of MeFC without cytotoxicity (0.25 mg/mL) significantly suppressed colony formation, a hallmark of cancer development, and completely inhibited the colony formation at 1 mg/mL. Collectively, these results suggest that MeFC exhibits a potent anticancer effect by suppressing the growth of oral cancer cells and colony formation via caspase- and mitochondrial-dependent apoptotic pathways in FaDu human hypopharyngeal squamous carcinoma cells. Therefore, the methanol extract of Ficus carcica leaves provide a natural chemotherapeutic drug for human oral cancer.
        4,000원
        25.
        2020.06 구독 인증기관 무료, 개인회원 유료
        HPT research studies and practices have been largely conducted in the corporate setting, leaving education as a neglected context despite its strong emphasis on performance in teaching, learning, and school management. In this study, we examine the application of the HPT standards and their effects on Korean teachers’ performance goal achievement for students. With HPT standards, we also investigate the interaction effect of teacher tenure on the relationship among HPT standards and goal achievement. The Hayes Process Model is adopted to examine the second-stage moderated mediation model. The findings support that the principle standards positively mediate the effect of the process standards on the teachers’ goal achievement, and teacher tenure moderates the HPT standards’ effects on goal achievement. The practical and theoretical implications of the results are discussed, as well as limitations and future research suggestions
        4,800원
        26.
        2020.03 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        Spontaneous motion is one of the most basic event types, but different languages use varying patterns to express it. For example, English usually encodes path information in prepositional phrases or adverbial particles, while Korean maps path information onto verbs (Talmy, 1985). This study predicts that this typological difference would affect English spontaneous motion expressions produced by Korean learners and analyzes two English-language speech corpora, one, the data from native speakers (600 recordings), and the other, data from L1-Korean learners of English (400 recordings). It finds that the learners significantly underuse satellite-framed patterns, but not verb-framed patterns, compared with the native speakers, suggesting that the L1 plays a role in their L2 production. The satellite-framed patterns, however, account for the greatest portion of spontaneous motion expressions in the L2 corpus, suggesting the dominant effect of input on L2 production. These findings lead to pedagogical implications concerning preventing L1 interference and fostering input-based L2 acquisition.
        5,200원
        27.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        CKD 추출액은 시멘트공정에서 발생한 폐기물인 CKD를 시멘트 원료로 재사용하기 위해 공정 방해물질로 작용하는 KCl을 추출한 폐수이며, 폐수처리시설 증설 등의 문제로 추출액 무방류 및 이를 재이용하고자 하였다. 이온교환법을 적용하여 KCl을 제거한 결과, 이온교환 후 추출액의 pH는 12.7 에서 pH 2 미만으로 감소하였으며 양이온교환수지의 H+가 이온교환을 거쳐 추출액에 용해되었음을 확인하였다. 이온교환의 선택성에 의해 Ca2+, K+ 순서로 제거되었으며, K+ 이온을 제거하기 위해 접촉시 간의 증가가 필요함을 판단하였다. 이온교환수지와 직접접촉시간이 약 6배 높은 접촉시간을 갖는 회분 식장치에서 연속흐름식장치 대비 4배 높은 K+ 제거 효율을, 7배 높은 Cl- 제거 효율을 확인하였다. 양이온교환수지의 H+가 음이온교환수지의 OH- 대비 1.2배 빠른 교환속도를 가짐을 추출액 pH 변화를 통해 확인하였다.
        4,000원
        28.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The present study was designed to determine the effect of barn or cycle of grazing on changes of biochemical metabolites in prepartum and changes of milk composition in postpartum of dairy cows. For this purpose, a total of sixteen 25 months old Holstein primiparous dairy cows were allocated in two groups (n=8) with an average body weight of 571.61 ± 35.30 kg (Barn) and 578.10 ± 39.20 kg (Grazing). The study was conducted from June 2018 to October 2018. Results revealed that barn raised dairy cows had a higher increase in their serum albumin and calcium level on day 14 prepartum. However, the level of palmitic acid, saturated fatty acid increased significantly, and the level of fat, oleic acid, γ-linoleic acid, arachidonic acid and unsaturated fatty acids decreased significantly in barn raised dairy cow’s milk on day 14 postpartum. There were no significant differences observed with respect to all other biochemical metabolites, fatty acids and minerals between barn raised and cycle grazing dairy cows during prepartum and postpartum. Our study results could serve to a better understanding of barn raised cow with respect to changes of biochemical metabolites in prepartum and changes of milk composition, fatty acids and minerals content in grazing dairy cows in postpartum for estimating their physiological status.
        4,000원
        36.
        2019.09 구독 인증기관 무료, 개인회원 유료
        Trifolium pratense leaves (red clover) has been used in Oriental and European folk medicine for the treatment of whooping cough, asthma, and eczema, and is now being used to treat and alleviate the symptoms, such as hot flushes, cardiovascular health effects that occur in postmenopausal women. However, relatively little scientific data is available on the physiological activity of this plant. Therefore, in this study, we investigated the anti-cancer activity of T. pratense leaves using methanol extract of T. pratense leaves (MeTP) on human FaDu hypopharyngeal squamous carcinoma cells. MeTP inhibited the viability of FaDu cells by inducing apoptosis through the cleavage of procaspase- 3, -7, and -9 and poly (adenosine diphosphate ribose-ribose) polymerase (PARP), downregulation of Bcl- 2, and upregulation of Bax, as determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, Live & dead assay, 4’6-diamidino-2-phenylindole stain, fluorescence-activated cell sorting analysis, and Western blot analysis. In addition, colony formation was slightly inhibited when FaDu cells were treated with a non-cytotoxic concentration (0.125 mg/mL) of MeTP and almost completely inhibited when cells were treated with 0.25 mg/mL MeTP. Collectively, these results indicate that MeTP induced cell apoptosis via caspase- and mitochondrial-dependent apoptotic pathways, and inhibited colony formation of cancer cells in FaDu human hypopharyngeal squamous carcinoma cells. These findings suggest MeTP should be considered for clinical development as a chemotherapeutic option in oral cancer.
        4,000원
        37.
        2019.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The Port of Pyeong Taek is located on the west coast, meaning that the difference between the rise and fall of tide is great (flood tide 1.8 to 2.9 knots, ebb tide 1.6 to 2.9 knots). Due to mainly N~NW’ly strong winds & high waves during winter, navigating as well as loading & discharging vessels must focus on cargo handling. The strong tidal and wind forces in the Port of Pyeong Taek can push an LNG carrier away from its berth, which will end up causing forced disconnection between the vessel’s cargo line and shore-side loading arm. The primary consequence of this disconnection will be LNG leakage, which will lead to tremendous physical damage to the hull and shore-side equipment. In this study, the 125K LNG Moss Type ship docked at No. 1 Pier of the Pyeong Taek is observed, and the tension of the mooring line during cargo handling is calculated using a combination of wind and waves to determine effective mooring line and mooring line priority management. As a result if the wind direction is 90° to the left and right of the bow, it was found that line monitoring should be performed bearing special attention to the Fore Spring Line, Fore Breast Line, and Aft Spring Line.
        4,000원
        39.
        2019.04 구독 인증기관·개인회원 무료
        Insect killing fungus Beauveria bassiana has been widely studied as a biological control agent. However, many studies have been focused on lab or field-based management. Herein this work, comparison of three B. bassiana strains was investigated under a molecular level. The whole genome sequences of ERL836, JEF-007 were analyzed by PacBio (35.5 Mb of ERL836 and 36.5 Mb of JEF-007) and ARSEF2860 referenced from GenBank (33.7 Mb). To compare the three strains, virulence, thermotolerance and chemical resistance were assayed. The transcriptomes of non-infecting B. bassiana and infecting B. bassiana against western flower thrips were analyzed using RNA-seq. This work can provide that genome features, functions, morphology and gene expression could be different under the molecular level, even if in the same species.
        40.
        2019.04 구독 인증기관·개인회원 무료
        The global biopesticide market was estimated to become about 4% of the total crop protection market in 2015, mainly due to variability of their efficacy, narrow spectrum or difficulties in long-term storage. Therefore, many people focus on overcoming these issues as a big trend. Suggested solutions include the investigation of synergy between microorganisms, the use of genetic engineering, improving the pesticide life shelf, etc. As a result, biopesticides market has grown by more than 17% over the last decade. In this context and aiming to develop new entomopathogenic fungi–based pest management tools, we constructed a fungal library by isolating insect pathogenic fungi from soil. A total of 581 isolates belonging to 35 species were isolated and characterized. Beauveria bassiana was the most abundant, representing 38.55% of the total strains, followed by Metharizium anisopliae (22.55%) and bubillosa (8.6). …% of the total isolates were highly virulent against Tenebrio molitor killing most of the treated insects in 2 to 3 days.
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