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        검색결과 220

        41.
        2019.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Nicotine is a component of tobacco products and is one of the most commonly abused substances that leads to addiction. Therefore, the present study was performed to investigate the behavioral pattern and toxicity by nicotine exposure in planarians. Basically, planarians were exposed to different concentration of nicotine for 5 min. To investigate detoxification effect, planarians were exposed to nicotine for 5 min, and treated glycyrrhizin for 5 min, then motility and seizure-like behavior were observed for 5 min. As a result, the motility of nicotine-exposed planarians decreased approximately more than 50% compared to freshwater control. However, the motility of glycyrrhizin-exposed planarians recovered than nicotineexposed planarians. In the assessment of seizure-like behavioral pattern, planarians exposed to nicotine showed head-bop or c-like type rather than screw-like or snake-like patterns. However, planarians exposed to glycyrrhizin showed no seizure-like behavior. To examine the oxidative stress response, planarians were cultured in fresh water containing 1 mM nicotine for 1 day. Planarians were homogenized and extracted to assay the contents of reactive oxygen species (ROS), lipid hydroperoxides (LH), glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). The result showed that a significantly higher level of ROS, LH indicated in planarians exposed to nicotine, on the other hand, glycyrrhizin-exposed planarians were significantly decreased ROS, LH levels. In conclusion, the motility decreased when planarians were exposed to nicotine, in a dose-dependent manner, whereas seizurelike behavior increased. Nicotine induced behavioral disturbances and cell toxicity in planarians were recovered by glycyrrhizin, suggesting a candidate substance for nicotine addiction treatment.
        4,000원
        42.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        자외선차단 화장품은 기능성 화장품 중의 하나로서, 유·무기 자외선차단물질이 함유되어 있다. 무기계 자외선차단제는 주로 산화아연, 이산화티탄 등이 있다. 무기계 자외선차단제는 입자의 지름이 60 ~ 100 nm로 자외선 A, B의 차단능이 좋은 것으로 알려져 있다. 또한 자외선을 포함한 태양광선에 대해 비활성이 크고 안전성이 우수하다. 그리고 유기계 자외선차단제처럼 피부에 흡수 또는 축적되지 않으므로 피부 자극이나 알레르기를 유발하지 않는다. 본 연구에서는 판상 무기안료인 마이카, 자외선차단 효과를 갖는 이산화티탄 나노입자, 소수성 실리카를 각각 계면활성제로 표면처리 하였고, 각 물질의 전하 차이에 따른 비화학적인 상호 인력 작용에 의해 마이카에 이산화티탄 나노입자, 실리카를 물리적으로 흡착시켰다. 이후, 소수성 표면처리제인 실란을 표면처리 하여 소수성을 갖는 자외선 차단 판상 마이카 복합체를 제조하였다. 자외선 차단 판상 마이카 복합체는 일반적인 나노입자 이산화티탄의 응집성을 개선하고 균일한 분산에 따른 자외선차단 효과가 증대되었으며, 소수성으로 표면처리를 하여 화장품 제형에서의 분산안정성을 크게 개선할 수 있었다. 안료의 표면전하는 제타전위로 평가하였으며, 제조된 자외선차단 마이카 복합체의 특성 평가는 FE-SEM, XRD, FT-IR, UV-VIS 등으로 확인하였다.
        4,000원
        43.
        2018.10 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The DEEP-South (the Deep Ecliptic Patrol of the Southern Sky) photometric census of small Solar System bodies produces massive time-series data of variable, transient or moving objects as a by- product. To fully investigate unexplored variable phenomena, we present an application of multi-aperture photometry and FastBit indexing techniques for faster access to a portion of the DEEP-South year-one data. Our new pipeline is designed to perform automated point source detection, robust high-precision photometry and calibration of non-crowded fields which have overlap with previously surveyed areas. In this paper, we show some examples of catalog-based variability searches to find new variable stars and to recover targeted asteroids. We discover 21 new periodic variables with period ranging between 0.1 and 31 days, including four eclipsing binary systems (detached, over-contact, and ellipsoidal variables), one white dwarf/M dwarf pair candidate, and rotating variable stars. We also recover astrometry (< ±1–2 arcsec level accuracy) and photometry of two targeted near-earth asteroids, 2006 DZ169 and 1996 SK, along with the small- (0.12 mag) and relatively large-amplitude (0.5 mag) variations of their dominant rotational signals in R-band.
        4,600원
        44.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Samples were collected from planktonic habitats of the fresh and brackish waters in Korea from August 2016 to May 2018. As a result, three genera and nine species were newly recorded in Korea. The unrecorded indigenous genera were Anathece, Chondrocystis and Geminocystis, and nine species were Anabaenopsis arnoldii, Anathece smithii, Chondrocystis dermochroa, Coelosphaerium aerugineum, Eucapsis microscopica, Geminocystis herdmanii, Microcystis panniformis, Synechococcus nidulans and Woronichinia karelica. Anathece smithii, Coelosphaerium aerugineum, Eucapsis microscopica, Microcystis panniformis and Synechococcus nidulans had been reported to inhabit freshwater, but these were found in brackish water in this study. Microcystis panniformis, which is a potential genus for causing green-tide, is taxonomically valuable in Korea.
        4,000원
        45.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Samples were collected from benthic and subaerophytic habitats of fresh and brackish water in Korea from April 2017 to April 2018. Accordingly, three genera and seven species were newly recorded in Korea. Three unrecorded genera were Cephalothrix, Cyanophanon and Toxifilum, and seven species were Anagnostidinema pseudacutissimum, Calothrix elenkinii, Cephalothrix komarekiana, Cyanophanon mirabile, Cyanosarcina chroococcoides, Leptolyngbya ectocarpi and Toxifilum mysidocida. Anagnostidinema pseudacutissimum and Cephalothrix komarekiana had been previously reported to inhabit freshwater, but these were found to be present in brackish water during the period of the present study. Also, Cyanosarcina chroococcoides previously reported to inhabit moorland waters and swamps, were found to be present in subaerophytic habitat.
        4,000원
        46.
        2018.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Phytoplanktons were collected from various environments including small marshes, small ponds, reservoirs and brackish water from March 2017 to November 2017. In this study, five species of family Scenedesmaceae were newly recorded in Korea. The genus Desmodesmus was newly reported in Korea. The newly recorded species are Scenedesmus nanus, S. praetervisus, Desmodesmus costato-granulatus, D. lunatus and D. spinulatus. S. nanus and S. praetervisus are known to occur in freshwater, but they were found in the brackish water in this study.
        4,000원
        47.
        2018.07 구독 인증기관·개인회원 무료
        Brand equity (BE) previously focused on consumers’ perceptions under brand marketing stimuli, they often used financial performance indicators for evaluating brand value (Aaker,1996;Keller,1993). However the primary stakeholders of a service brand are employees (Brexendorf & Kernstock,2007).Thus, the enhancement of employee- based BE could be an important topic for in-depth investigation in the fields of brand and internal marketing. Morhart (2009) was the first to introduce the concepts of brand-specific transformational leadership (TFL) and brand-specific transactional leadership (TRL) based on employees’ brand-building behavior. Theory asserts that leaders should endeavor to influence employees through the internalization of brand values and a brand-based role (Morehart,2001) . In the process of brand internalization, leaders with brand experience and brand knowledge should also uphold and constantly reaffirm brand values because they're more capable than ordinary leaders to clearly convey brand values (Hoffman,1999). For this reason, brand-specific leadership based on employee brand-building behaviors is the focus of this study. This study adopts hierarchical linear modeling for individual and organizational-level analyses. This research to investigate (1)whether TFL and TRL have directly affect employee-based individual-level BE.(2)whether TFL and TRL have indirectly affect employee-based BE as an individual-level mediator.(3)how managers use brand-specific leadership to elicit employees’ perceived brand value congruence for improved employee-based BE.
        50.
        2018.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        말라위는 농업생산성 향상을 위해 관개시설 설치를 적극적으로 확대하고 있는데. 주로 외국의 원조에 의존하고 있다. 따라서 말라위의 효율적인 관개시설 구축을 위해 우리나라의 영산강유역농업종합개발사업(이하 영산강사업) 사례를 검토한 후 정책적 시사점을 제시하였다. 우리나라의 영산강사업은 유관기관들의 체계적인 협업 시스템으로 장기간에 걸쳐 시행되었다. 따라서 말라위의 중장기적인 관개시설 구축을 통한 농업생산성 향상을 위해서는 정부의 강력한 의지와 해당 사업을 주도적으로 시행할 수 있는 기관의 역할을 분명히 할 필요가 있다. 이를 위해서는 법적으로 규정해야 할 것이다. 현재 말라위의 사회경제적 여건은 우리나라의 영산강사업 추진 시기와는 매우 상이하다. 또한 한국의 영산강사업은 중장기적으로 걸쳐 시행되면서 각 과정에서 시행착오를 통한 노하우(know-how) 및 기술이 축적되었다. 따라서 말라위도 영산강사업과 같은 대규모 국책사업을 일괄적으로 시행하기 보다는 테스트 베드를 거쳐 말라위 여건에 맞게 시행할 필요가 있다. 영산강사업은 시행 초기에 환경문제가 크게 부각되지 않았지만, 90년대 후반부터는 ‘환경’에 대한 경각심이 커져 현재 영산강사업 5단계 설치는 중단된 상태이다. 따라서 말라위에서도 이러한 환경문제 및 제반 정치경제적 여건에 대한 면밀한 검토가 필요하다. 다만, 영산강사업은 벼농사를 위한 관개시설 위주의 사업이므로, 밭작물 위주의 관개시설은 그 형태 및 시사점이 달라질 수 있다 . 그리고 우리나라 영산강사업은 장기간에 걸려 축적된 노하우와 기술이 단계적으로 적용된 것으로 , 각 토목기술별로 말라위에 적용 가능한지는 추후 검토가 필요할 것이다 . 이러한 정책적 한계점은 추후 연구과제로 남겨둔다.
        4,200원
        55.
        2017.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Samples were collected between August 2016 and May 2017 at Sangju-si, Gyeongsangbuk- do, Jeju-do, and Uljin-gun, Gangwon-do. As a result, one genus and six species were newly recorded in Korea. The unrecorded indigenous genus was Borzia, and the six species were Anagnostidinema acutissimum, Komvophoron bourrellyi, Hydrocoleum stankovicii, Borzia trilocularis, Phormidium tinctorium and Pseudanabaena lohchoides. Phormidium tinctorium and Pseudanabaena lohchoides had been reported to inhabit freshwater, but in this study, these were found in brackish water. It had also been reported that B. trilocularis trichomes are composed of up to 8 cells, but in this study, a maximum of 10 cells was observed.
        4,000원
        56.
        2017.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Rubus coreanus is known to have diverse biological properties, such as free radical scavenging activity and antibacterial activity. In the present study, Rubus coreanus leaf and stem extract (RLSE) was used in boar semen preservation whether it has a beneficial effect on assisted reproductive technology (ART) in mammals. Boar spermatozoa were preserved in Beltsville thawing solution (BTS) in the presence of varying concentrations of RLSE (0-10 μg/mL). Sperm motility, sperm viability, and intracellular reactive oxygen species (ROS) levels were examined after 2 days of preservation. The percentage of total motile spermatozoa and progressive motile spermatozoa improved in the spermatozoa preserved with 0.5 μg/mL RLSE. Higher proportions of viable spermatozoa were seen in the presence of 0.5 and 1 μg/mL RLSE than in the control. Intracellular ROS levels decreased when the spermatozoa were preserved in BTS with 0.1–1 μg/mL RLSE. In order to examine the bacterial growth, E. coli was added to liquid semen diluted with antibiotics-free BTS in the presence or absence of RLSE. No anti-bacterial activity of RLSE against E. coli was observed during liquid semen preservation. Although there was no inhibition of E. coli growth, the addition of RLSE might help improve sperm motility and viability during boar semen preservation, suggesting it as a potential reagent for ART in mammals.
        4,000원
        57.
        2017.06 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        We conduct BVRI and R band photometric observations of asteroid (5247) Krylov from January 2016 to April 2016 for 51 nights using the Korea Microlensing Telescope Network (KMTNet). The color indices of (5247) Krylov at the light curve maxima are determined as B - V = 0:841  0:035, V -R = 0:4180:031, and V -I = 0:8710:031 where the phase angle is 14.1◦. They are acquired after the standardization of BVRI instrumental measurements using the ensemble normalization technique. Based on the color indices, (5247) Krylov is classi ed as a S-type asteroid. Double periods, that is, a primary period P1 = 82:188  0:013 h and a secondary period P2 = 67:13  0:20 h are identi ed from period searches of its R band light curve. The light curve phases with P1 and this indicate that it is a typical Non-Principal Axis (NPA) asteroid. We discuss the possible causes of its NPA rotation.
        4,000원
        58.
        2017.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        이 연구의 목적은 선교적 리더십을 회복하기 위해 교회 리더십을 선교신학적 관점으로 분석하고 적용하고자 한다. 교회 리더십을 성경적, 신학적, 선교적 관점으로 분석하면, 성경적으로 교회 리더십은 모든 열방을 향한 보편적인 성격으로서의 선교적 의미를 담고 있고, 신학적으로 하나님 의 선교 신학은 선교의 주체가 교회가 아닌 하나님이라는 것을 재발견하게 한다. 그리고 선교적 관점에서 선교적 교회론은 교회의 선교적 본질을 다시금 깨닫게 하는데, 선교적 교회론에서 중요한 요소는 바로 선교적 리더십이다. 선교적 리더십의 적용으로서 한국교회의 실례를 들어 창조적, 통전적, 에큐메니칼, 개혁적 리더십의 특성을 이 연구는 다루고 있다. 즉, 창조주 하나님의 능력의 확장으로써의 창조적 리더십, 영혼구원과 사회적 책임을 통합하는 통전적 리더십, 더불어 살기를 지향하는 에큐메니 칼 리더십, 개혁영성을 회복하는 개혁적 리더십이다. 교회의 선교적 리더십 적용은 교회에 하나님 나라를 이루어가는 본질적 리더십의 회복의 가능성을 열어준다.
        7,700원
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