검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 190

        41.
        2020.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Behavioral response to a diel photoperiodicity (500 lx for 16 h, 5 lx for 4 h and < 0.5 lx for 4 h) and phototactic characteristics in dark conditions were examined with Siberian sturgeon Acipenser baerii (Chondrostei, Actinopterygii) prelarvae. Siberian sturgeon prelarvae represented both qualitative and quantitative changes in their behavioral patterns according to different light intensities in a diel photoperiodicity. Under daylight conditions (500 lx), prelarvae displayed saltatory changes of behavioral features with ages (Day 0-Day 9) in a general order of swimming-up/drifting, swimming in the upper water column, benthic swimming with rheotaxis, schooling and postschooling behavior. Compared to daylight conditions, prelarvae tended to show more benthic performances and quantitative reductions of schooling and postschooling behaviors under dimlight conditions (5 lx). Under dark conditions (< 0.5 lx), prelarvae exhibited a fairly uniform behavioral pattern characterized by the benthic swimming across the bottom of the tank. From phototaxis tests under dark conditions, navigational responses of prelarvae to a spotlight illumination were quantitatively changed as their ages increased. The phototactic responses reached the peak on Day 2, continued until Day 4, and then gradually decreased until Day 8. A partial recovery of positive phototaxis was observed on Day 9. Data from this study suggest that the diel light cycle as well as the light intensity of each interval in the cycle should be considered as important components of a practical guide for evaluating fitness and developmental states of artificially propagated Siberian sturgeon prelarvae.
        4,500원
        44.
        2020.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The prickly pear cactus (Opuntia), native to Mexico, has grown in popularity and is locally grown and adapted on Jeju Island. The fruits of this cactus species are in particular widely employed as raw materials, which are then processed into various food and medicinal items, including chocolates and vitamins, for purposes of human consumption. Because this crop has been dubbed one of Jeju’s iconic agricultural crops, research studies elucidating the prickly pear cactus’ medicinal properties, including antioxidant activity, of this particular plant and related cultivated species have demonstrated high value to the scientific community. Currently, consumers do not purchase products f or c onsumption a lone, but in a ddition f or t heir added health benef its. The present study in particular honed in on two species of prickly pear cactus that are cultivated on Jeju Island which include: ‘Baeknyeoncho’ (Opuntia ficus-indica) and ‘Cheonnyeoncho’ (Opuntia humifusa). From these species, s pecif ci p lant p arts i ncluding t he f lower, mature and y oung stems, roots, a nd f ruit w ere subjected to further antioxidant analysis, which included the determination of polyphenol, flavonoid, DPPH radical, ABTS radical, and anthocyanin levels. These particular antioxidants were determined during two seasons, over the course of the summer and winter. Results revealed that the antioxidant activity for both species was more active during the summer season. Antioxidant levels occurred at the highest rates within t he flowers o f the c actus plants. However, of significant note was that the cactus stem, in both mature and young plants, possessed higher antioxidant activity compared to those of the fruit that is currently employed for commercial purposes.
        4,000원
        46.
        2019.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        최근 기능성 게임의 교육적인 활용에 대한 관심이 증가하면서, 게임의 교육적 효과성에 대한 많은 연구들이 이뤄지고 있다. 본 논문에서는 인지기능 향상을 위한 기능성 게임인 ‘바우바우 프렌즈’를 개발했다. 이 콘텐츠는 인지기능 중 집행기능(Executive function), 지속적 주의력 (Sustained attention), 분리적 주의력(Divided attention)을 다루고 있다. 본 연구에서 개발된 게임의 유용성을 증명하기 위해 EEG 실험을 수행했으며, 게임 전 뇌파와 게임 진행 중 뇌파를 측정하여 비교분석했다. 결과적으로 지속적 주의력 게임(Simon)과 분리적 주의력 게임(Cooking)이 인지기능 향상에 긍정적인 효과가 있는 것으로 나타났다. 보다 아동의 인지기능 향상이라는 명확한 검증을 위해서는 추후 아동을 대상으로 한 EEG 실험을 추가로 수행할 필요가 있다.
        4,200원
        49.
        2019.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Amine-functionalized graphene was synthesized via a one-step solvothermal method and used as a metal-free cathode for non-aqueous lithium–oxygen batteries. The material delivered an outstanding specific capacity of 19,789 mAh/g at a current density of 200 mA/g as well as better cycling stability than graphene without the amine functional group. This improvement was attributed to the electron-donating effect of the amine groups and appropriate mesopore volume, which can promote the penetration of oxygen, electrons, and lithium ions, as well as accommodate more discharge products, Li2O2 in Li–O2 batteries. Amine-functionalized graphene has an amine functional group on the carbon surface, which improves the electrical conductivity of carbon and provides electrochemical active sites for oxygen absorption reactions.
        4,000원
        52.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        High-level heteroatom, N and S, dual-doped graphene with an improved mesoporous structure was fabricated via facile in situ carbonization and used as metal-free cathode for non-aqueous lithium oxygen batteries. The prepared cathode delivered an ultrahigh specific capacity of 22,252 mAh/g at a current density of 200 mA/g as well as better cycling reversibility because of the larger and copious mesopores, which can promote the penetration of oxygen, electrons, and lithium ions and the ability to accommodate more discharge products, e.g., Li2O2, in Li–O2 batteries. The material had a high level of heteroatom co-doping in the carbon lattice, which enhanced the electrical conductivity and served as active sites for the oxygen reduction reaction.
        4,000원
        53.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, we investigate to determine quality characteristics, fatty acid composition and cytotoxic effect of extracts and fractions from whole Lycopus lucidus Turcz. roots. Additionally, we evaluated cytotoxic activity against the growth of human fibrosarcoma cells (HT-1080) and human gastric adenocarcinoma (AGS), human colon cancer cell (HT-29) lines using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Acetone+methylene chloride (A+M) and methanol (MeOH) extracts from L. lucidus Turcz. were obtained through solvent extraction. Then we further fractionated both extracts with n-hexane, 85% aq. MeOH, n-butanol (n-BuOH) and water. In fatty acid composition, L. lucidus Turcz. contained 33.2% of 18:1n-9 and 1.81% of 18:3n-3, respectively. The incorporation of treatment with A+M and MeOH extracts and n-hexane, 85% aq. MeOH, n-butanol (n-BuOH) and water fractions dose-dependently increased cytotoxicity against the growth of HT-1080 and AGS, HT-29 cancer cells (p<0.05). The A+M extract had a higher inhibitory effect on the growth of all cancer cells in comparison to MeOH extract. Among the fractions, the 85% aq. MeOH and n-hexane fractions showed a higher inhibitory effect after proliferating the three cancer cells. These results suggest that the 85% aq. MeOH and n-hexane fractions have a potential to inhibit the growth of human cancer cell lines.
        4,000원
        55.
        2018.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this paper was to investigate the comparison of balance and muscle strength between dominant and non-dominant legs in adults. Thirty adults in their 20s participated in this study. The dominant and non-dominant legs were selected based on the dominant hands of the target. The subject's muscle strength of legs was measured with Nicholas MMT, and the balance was measured with BIO-Rescue. We compared the dominant and non-dominant legs based on the results. The result, indicated no statistical difference on balance and muscle strength between dominant and non-dominant legs(p>.05). The results of this study will be helpful in setting the effective treatment direction and treatment level, and in controlling posture, balance and motor function.
        4,000원
        1 2 3 4 5