검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 19

        1.
        2023.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 전라북도 군산시 백악기 산북동층의 전석에서 발견된 소형 새 발자국 화석을 간략히 기재하고, 척추동물 발자국 화석을 포함한 산북동층 퇴적 시기를 확인하기 위해 산북동층 응회암질사암에서 쇄설성 저어콘을 분 리하여 S H RIMP U -Pb법 절대연령 분석을 실시하였다. 소형 새 발자국 화석은 보존상태가 양호하지 않으나, 보행렬을 이루는 두 개의 발자국과 세 개의 개별 발자국으로 구분된다. 이들은 물갈퀴가 없고, 비대칭이며 가느다란 세 개의 발 가락으로 걷는 소형 새 발자국이다. 보행렬을 이루는 발자국은 Koreanaoris dodsoni?, 개별 발자국은 Koreanaornis ichnosp.로 동정하였다. 본 연구는 산북동층 사족동물 발자국 화석 군집이 수각류, 조각류, 익룡과 새 발자국으로 구성 되어 있었음을 의미한다. 절대연대 분석 결과, 산북동층 퇴적시기의 최대지질연대는 112.5±5.8 Ma로 중생대 백악기 압 트절(Aptian)에 해당하며, 경상분지 진주층 하부에 대비될 수 있다. 그러므로 산북동층의 백악기 소형 물떼새 발자국 화 석(Koreanaornis)은 국내에서 가장 오래된 것으로 추정된다.
        4,200원
        2.
        2020.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The carbon anode material for lithium-ion battery was prepared by pyrolysis fuel oil and waste polyethylene terephthalate (PET) additive. The pitch was synthesized as a medium material for carbon anode by heat treatment. The waste PET additive improved the softening point and thermal stability of the pitch. La and Lc of the anode material (heat-treated pitch) increased at higher treatment temperature but decreased by waste PET additive. The electric capacity was evaluated based on effects of defective cavity and developed graphite interlayer, respectively. When the La and Lc of the anode material decreased, the electric capacity by cavity increased based on defective graphite structure. Therefore, the addition of waste PET causes the improved capacity by the cavity. The anode material which has a high efficiency (over 95%) and C-rate (95%, 2 C/0.1 C) was obtained by controlling the process of heat treatment and PET addition. The mechanism of lithium-ion insertion was discussed based on effects of defective cavity and developed graphite interlayer.
        4,000원
        3.
        2020.08 KCI 등재 구독 인증기관 무료, 개인회원 유료
        LA-MC-ICP-MS zircon U-Pb dating was conducted to constrain the timing of fossil formation and the depositional age of the uppermost Jinju Formation located in Natural Monument No. 534 (Tracksite of Pterosaurs, Birds, and Dinosaurs in Hotandong, Jinju), and 87 Cretaceous, 1 Precambrian, and 2 Jurassic zircons were obtained from 90 valid analytical points. Most Cretaceous zircons were found to have a youngest graphical peak age of ca. 106.5 Ma, suggesting the depositional age of the uppermost Jinju Formation. Based on this study and previous works, the average sedimentation rate of the Jinju Formation was calculated to be approximately 0.17-0.31 mm/year in the Milyang Subbasin, and the Cretaceous zircons of the uppermost Jinju Formation seem to have originated mainly from the western or northwestern parts of the Gyeonggi Massif. Unlike the Nakdong and Hasandong formations of the Sindong Group, most zircons analyzed in the uppermost Jinju Formation were Cretaceous. This suggests that volcanic activity occurred in the area closer to the Gyeongsang Basin due to the roll-back of subducting paleo-Pacific Plates during the Jinju period.
        4,600원
        6.
        2018.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        울산 울주군 대곡리 공룡 발자국 화석산지(울산광역시 문화재자료 제13호)에서 익룡 발자국이 새롭게 발견되었다. 이들은 울산 지역 백악기 퇴적층에서 처음 보고된 것이다. 이 발자국 화석산지는 익룡 발자국이 집중적으로 보고되었던 경상남도 해안 지역과 지리적으로 비교적 원거리에 위치하고, 층서적인 차이도 있다. 본 연구에서는 대곡리의 익룡 발자국 및 보행렬을 기재하였고, 백악기 동안 한반도에서 활동한 익룡의 시공간적 분포를 논의하였다. 대곡리에서 발견된 익룡 발자국은 형태적인 특징에 근거해 Pteraichnus ichnosp.로 분류할 수 있다. 대곡리 익룡 발자국을 포함하여 지금까지 알려진 한반도 익룡 발자국의 분포를 근거로 할 때, 한반도의 익룡들은 적어도 약 1억2천 만 년 전(120 Ma, 전기 백악기)부터 8천만 년 전(80 Ma, 후기 백악기)까지 약 4천만 년 동안 생존하였으며, 분지 규모나 특정 퇴적 환경에 관계없이 다양한 퇴적 환경에서 서식하였다. 그리고 대곡리 일대에서 용각류, 조각류, 수각류, 익룡, 새 그리고 악어류 발자국이 함께 산출되는 것은 이곳의 백악기 척추동물 생흔 다양성이 매우 높았다는 것을 의미한다.
        4,800원
        7.
        2018.04 구독 인증기관·개인회원 무료
        Control mating is important aspect in bee breeding programs. The technique of artificial insemination is the possible one that can surely control mating of the selected drones with the virgin queen. This is the first time applied artificial insemination technique to control mating of A. cerana in Korea. Altogether 18 queens were artificially inseminated, and 2,000 drones of Korean A. cerana were used to evaluate amount of semen collection. Semen of A. cerana is much difficult to separate from mucus in comparing with A. mellifera. The average amount of semen can be collected from one A. cerana drone was 0.09 μl, whereas the A. mellifera was more than 6 times (0.58 μl semen per A mellifera drone). Obtaining 1 μl of semen have to collect from 11.94 drones that successful semen ejection and have to kill 17 A. cerana drones. Queens artificially inseminated with 4 μl of semen (once insemination) or 8 μl of semen (twice insemination, each with 4 μl of semen) started laying egg later than naturally mated queens 5.3 and 2.5 days, respectively. The onsets of oviposition of artificially inseminated queens were 12.5 to 15.3 days. Queens received twice inseminations started laying eggs 2.8 days earlier than those received only once insemination. Artificially inseminated queens produced exclusively brood and were similar as the naturally mated ones. The brood production of the queens received once insemination with 4 μl of semen was insignificantly different than those received twice inseminations or naturally mated ones, suggesting that one artificial insemination with 4 μl of semen is favorable.
        8.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 우리나라의 대표적인 자연사박물관인 고성공룡박물관의 관람객 수를 통계적으로 분석하였고, 관람객을 대상으로 만족도를 조사하였다. 그 결과, 2005년부터 2014년까지 지난 10년 간 누적 관람객 수는 약 341만 명이었다. 연간 최대 관람객 수는 약 44만 명이며, 연간 최소 관람객 수는 약 30만 명으로, 연평균 관람객 수는 약 34만 명이었다. 전체 관람객 중에서 개인 관람객의 누적 인원은 약 280만 명으로 82.0%를 차지하였으며, 단체 관람객 누적 인원은 약 61만 명으로 18%이었다. 월별 방문 관람객 수를 분석한 결과, 8월에 약 53만 명으로 가장 많고, 2월에 약 14만 명으로 가장 적었다. 개인과 단체 관람객의 방문 패턴은 차이를 보였는데, 개인 관람객은 8월에 가장 많았고, 12월이 가장 적었다. 반면, 단체 관람객은 10월에 가장 많았고, 2월에 가장 적었다. 관람객들의 거주 지역은 대체로 지리적 접근성과 거주 지역의 인구수에 비례하는 것으로 나타났다. 관람객들의 만족도 조사 결과, 대체적으로 높은 만족도(평균 4.1)를 보였으나, 일부 시설에 대해서는 개선이 필요한 것으로 조사되었다. 관람객의 방문 횟수와 재방문 의사에 대한 설문 조사 결과, 192명 중 102명(53.1%)이 2회 이상 방문하였고, 198명 중 178명(89.9%)은 재방문 의사가 있는 것으로 나타났다. 본 연구의 조사 결과는 고성공룡박물관의 중장기적 발전 방안 마련을 위한 현황 분석 및 기초 자료로 활용될 수 있을 것이다.
        5,100원
        9.
        2017.04 구독 인증기관·개인회원 무료
        Due to their environmental and economical consequences, invasive species have become a major concern worldwide. Among them, the yellow-legged hornet, Vespa velutina, is a keen hunter of domestic honeybees. They use olfactory cues from the prey to assess food information. In this study, we investigated the attraction behavior of V. velutina to honeybee pheromone under outdoor conditions. Nine honeybee pheromones were tested and compared in order to find the best attractant. When testing specific compounds, the honeybee queen pheromone, homovanillyl alcohol, proved highly attractive.
        10.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        목 적 : GRAPPA 기법을 이용하는 검사에서 GRAPPA factor는 k-공간 내에 누락시 킬 신호의 양을 결정하고 검사시간을 줄이는 변수이다. 하지만 GRAPPA factor가 증가할수록 영상의 SNR이 저하되고 인공물이 증가하는 제한점이 있다. 따라서 본 연구에서는 GRAPPA factor와 ACS Line 수를 변화시켜 영상 화질과의 상관관계를 평가하여 분석하고자 하였다. 대상 및 방법 : VIBE sequence를 사용하여 GRAPPA factor를 2, 3, 4, 5로 ACS Line의 수는 20, 40, 60, 80, 100, 120로 증가시키고 검사하였다. 화질 평가를 위해 영상의 SNR을 측정하였고 GRAPPA 기법을 이용하지 않은 영상과 GRAPPA 기법을 이용한 영상의 유사성(SSIM)을 평가하였다. 또한 GRAPPA factor를 2, 3, 4, 5로 고정하였을 때 ACS Line과 SNR, ACS Line과 SSIM의 상관관계분석을 실시하였다. 결 과 : GRAPPA factor가 증가 할수록 SNR은 저하되었고 같은 GRAPPA factor의 조건에서 ACS line의 수가 증가 할수록 SNR은 증가되었다. GRAPPA 기법을 이용하지 않은 영상과 GARPPA기법을 이용한 영상의 유사성 평가에서는 GRAPPA factor가 증가 될수록 SSIM은 저하되었고 같은 GRAPPA factor의 조건에서 ACS Line의 수가 증가 될수록 SSIM은 1에 가까워졌다. ACS Line의 수와 SNR의 상관관계분석 결과 GRAPPA factor가 2일 경우 Pearson 상관계수가 0.291, GRAPPA factor가 3일 경우 0.458, GRAPPA factor가 4일 경우 0.779, GRAPPA factor가 5일 경우 0.88로 나타났다. ACS Line의 수와 SSIM의 상관관계분석 결과 GRAPPA factor가 2일 경우 Pearson 상관계수가 0.787, GRAPPA factor가 3일 경우 0.792, GRAPPA factor가 4일 경우 0.918, GRAPPA factor가 5일 경우 0.946로 나타났다. 결 론 : GRAPPA 기법을 이용하는 검사에서 GRAPPA factor를 증가시킬 경우 검사시간이 감소하지만 SNR이 저하되고 인공물이 증가하는 제한점이 있다. 따라서 GRAPPA 기법을 이용하였을 때 검사에 영향을 주지 않은 시간 내에서 ACS Line의 수를 최대로 사용하면 SNR 증강 효과와 더불어 인공물을 개선할 수 있고 GRAPPA factor가 높을 경우 ACS Line의 수를 증가시키면 개선효과가 더 클 것으로 사료된다.
        4,000원
        11.
        2016.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구는 발자국 및 보행렬 화석의 발굴 방법과 이의 적용에 관한 것이다. 공룡, 익룡 및 새 발자국과 같은 척 추동물의 발자국과 보행렬 화석들은 공룡 등과 같은 실체 화석들과는 달리 일반적으로 특정 방향을 향하여 길게 진행 한 흔적을 남기거나 넓은 층리면에서 발견되며, 평면적인(2차원적인) 특성을 가진다. 이와 같은 발자국 화석의 특성을 반영하여 비교적 넓은 층리면에 보존된 발자국 화석을 발굴하기 위해 새로운 방법을 고안하였고, 이 방법을 5곳의 발 자국 화석 발굴 현장에 적용하였다. 그 결과, 발자국 화석산지에서 공룡, 익룡, 새 발자국과 보행렬 화석들을 성공적으 로 발굴하였다. 그리고 다양한 발굴 사례에 근거하여, 발자국 화석 발굴의 단계별 과정과 세부 사항을 제안하였다.
        5,400원
        12.
        2012.03 구독 인증기관 무료, 개인회원 유료
        Opioid receptors have been pharmacologically classified as µ, δ, κ and ε. We have recently reported that the antinociceptive effect of morphine (a µ-opioid receptor agonist), but not that of β-endorphin (a novel µ/ε-opioid receptor agonist), is attenuated by whole body irradiation (WBI). It is unclear at present whether WBI has differential effects on the antinociceptive effects of µ-, δ-, κ- and ε-opioid receptor agonists. In our current experiments, male ICR mice were exposed to WBI (5Gy) from a 60 Co gamma-source and the antinociceptive effects of opioid receptor agonists were assessed two hours later using the hot water (52℃) tail-immersion test. Morphine and D-Ala2,N-Me-Phe4,Gly-ol-enkephalin (DAMGO), [D-Pen2-D-Pen5]enkephalin (DPDPE), trans-3,4-Dichloro-N-methyl-N-[2-(1-pyrrolidinyl)- cyclohexyl]¬benzeneacetamide (U50,488H), and β-endorphin were tested as agonists for µ, δ, κ, and ε-opioid receptors, respectively. WBI significantly attenuated the antinociceptive effects of morphine and DAMGO, but increased those of β-endorphin. The antinociceptive effects of DPDPE and U50,488H were not affected by WBI. In addition, to more preciously understand the differential effects of WBI on µ- and ε¬opioid receptor agonists, we assessed pretreatment effects of β-funaltrexamine (β-FNA, a µ-opioid receptor antagonist) or β-endorphin1-27 (β-EP1-27, an ε-opioid receptor antagonist), and found that pretreatment with β-FNA significantly attenuated the antinociceptive effects of morphine and β endorphin by WBI. significantly reversed the β-EP1-27 attenuation of morphine by WBI and significantly attenuated the increased effects of β-endorphin by WBI. The results demonstrate differential sensitivities of opioid receptors to WBI, especially for µ- and ε-opioid receptors.
        4,000원
        13.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Recently, increasing interests in local foods have been highlighted along with active efforts and activities from autonomy organizations to develop local cultures and promote local economies by generating value added products and profits through the development of local foods. Subsequently, useful effects might result by making local foods attractive to tourists, such as by using indigenous Gimpo products to makc menu items that incorporate the social, economic, and cultural aspects of the Gimpo area, and contributing to its food culture, the development and use of its indigenous products, and promoting local restaurant businesses, etc. The items of the Survey used to select the local food menu items to be developed were limited to ideas offered by expert groups, and were implemented by a new menu developmεnt process. In order to derive the menu items to develop, the following method was applied: a brainstorming session with experts to generate and draft ideas, a questionnaire to chefs and cooks in special grade hotels is Seoul to select thε menu items to develop from those drafted, and sensory evaluations by experts to evaluate the developed items. Frequency analysis and technical statistical analysis were performed using the SPSS 12.0 program package, where 13 kinds of local foods were ultimately developed using indigenous products of Gimpo. The developed local food menu items werε rice & grape sujaebi, grape sikhae, fried rice embryo bud, grape yanggaeng, rice pancakes, rice spaghetti, grape seed oil dressing, grape sauce, rice pizza, grape pie, rice & grape ice cream, grape chocolate, and rice roll cakes.
        4,000원
        14.
        2007.04 KCI 등재 구독 인증기관·개인회원 무료
        Sulfur is commonly used in Asia as an herbal medicine to treat inflammation and cancer , a nd potent chemo preventi ve effects have been demons tra ted in various in vivo and in vitromodels for s ul fur-containing compounds found in natura l1y occurring product s. Here, we 1'eport the growth inhibitory and apoptosis-related effects of a n ewly developedhigh-puri ty edible sulfur(ES) on immo1'tali zed human o1'al ke1'atinocytes(IHOKs) and on oral cancer cells representing two stages of oral cancer (HN4‘ HN12) based on an 3-(4,5-Dimethylthiazol-2-yl) -2.5- diphe n yltetrazolium bromide(MTI) assay, Western blotting, cell cycle analysis, and nuclear staining. The puri ty of the ES used in thi s study was ve1'ified by high performance liquid chromatog1'aphy (HPLC) , ami no acid analysis and energy dispersive spectroscopy(EDS). ES inhibited the prolife1'ation of imrnortalized and ma lig nant o1'al kerati nocytes in a dose- and time-dependent manne1' FITC-Annex.in V staining, DNA fragmentation t esting. and Hoechst 33258 s taining revealed that ES inhibits cell growth via apoptosis. ES bl ocked cell-cycle prog1'ession at t he sub-Gl phase‘ wi th decreased expression of cyclins Dl, D2‘ and E, and their activating partn ers cdk2‘ cdk4‘ and cdkfì, and a concomitant induction of p53 and p21/WAF1. Furthe1'more, ES treatment in creased the cytosolic level of cytochrome c and resulted in caspase- 3 activation‘ and thi s effect was co1'1'elated with Bax up-regulation and Bcl-2 down-1'egulation Taken together‘ these data suggest that ES is a potential chemopreventive and chemotherapeut ic agent fo r oral ca ncer
        15.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        1'0 determine Lhe ll1echanism of cell c1eath incluced by iron chelators. we explored the pathways of the three structurally relatecl ll1 itogen-activatecl protein(MAP) kinase subfami li esduring iron cbelator- inclucecl apoptosis ancl differentiation of oral precancerous ancl cancel‘ cells. The iron chelator c1 eferoxamine(DFO) exertecl potent timeancl c1ose-c1epenclent inhi bitory effects on the growth of IHOK and HN4 cells The major mechanism of growth inhibition following DFO treatment was fOllncl to be apoptosis incluction. as assessecl by annexin V-FITC staining. cell cycle analysis‘ DNA lacldering, a ncl Hoechst staining. We report that DF'O s trongly activates the p38 MAP kinase and extracell ular signal- regu lated kinase(ERK). but c10es not activate the c-Jun N-terminal kin ase/ stl않s-activaLecl protein kinase(JNK/8APK) . Of the three MAP kinase blockers usecl‘ the selective p38 MAP kinase inhibitor 8ß203580 ancl ERK inhibitor PD98059 protected oral premaIignant ancl malignant cells againsL iron chelator- nclllced cell death. which incl icates that the p38 MAP kinase serves as a major mecliator 01' apoptos is induced by this iron chelator DFO also evoked the release of cytochrome c from mitochondria, and incluced the activation of caspase-3 ancl caspase-8 in oral cancer cells, which suggests that apoptosis occurs via the mi tochoncl ri on - mecl iaLed pathway. DFO enhanced the expression of Bax in IHOK ancl HN4 cells. consistent witll thei r p53 status Moreover. DFO downregulatecl the expression 01' Bcl-2 in oral cancer cells. which suggests that DFO- incluced apoptos is 01' oraJ cancer and precancerous cells may be mediatecl by an increase in the ratio of pro-apoptotic to anti-apoptotic proteins. ln terestingJy, trcatmcnt 01' IHOK ancl HN4 cel ls with 8B203580 abolishecl cytochrome c release‘ as wel l as the activation of caspase-3 and caspase-8. DFO suppressecl the expression of epithelial di ffe rentiation markers, such as involucrin, t ransglutaminase II. CK6. and CK19. ancl this suppression was blockecl by p38 ancl ERK MAP kinase ll1hlbltors The oral premalignant(IHOK) ancl malignant cell s(I-lN4) showed differential responses to DFO with respect to the expression of cel l cycle regulatory proteins. cell growth. ancl apoptosis. Coll ectively. the current study reveals that p38 MAP kinase plays an ill1 portant role in iron chela tor-mecliatecl cel l cleath and in the suppression of differentiation of oral premalignantandmalignanLcell s.by activating a c10wnstream apoptotic cascade that executes the ceIl c1eath pathway
        16.
        2005.10 KCI 등재 구독 인증기관·개인회원 무료
        뻐ny studìes have shown the anti-proli ferative effects of irondeprivation on cancer cell s‘ but the effects 01' iron-chelators on oral cancer have not been clearly elucidated , To investigate the effects of an iron chelato r, desferrioxamine( 01"O).on the growth of ilIllTIortali zed human o1'al ke ratinocytes(IHOK), primary oraJ cancer cel ls(HN4)‘ metastatic oral cancer cell s(HN12) , and human skin keratìnocytes(HaCaT) in the MTr assay, three-dimensional(3D) raft cul tmes, Western blott ing, cell cycJ e analysis‘ nuclear staining‘ and cytochrome c expression for apoptosis s ig naling pathway were used OFO inhibited the growth of immortalized IHOK and HaCaT and mal ignant HN4 and HN12 keratinocytes in a time- and dose-dependent manner according to the MTT assay, The 3D organotypic cu l tu re also revealed that OF'O-treated cells showed less epithelial maturation, less surface keratinizati on‘ and de creased epithelia l thickness, The major mechanìsm of growth inhìbition with the micromolar 0 1"0 treatment was by the induction of apoptosis‘ which was supported by nuclear OAPI staining, ONA fragmentation analysis, and J10w cytometric analysis for sub-Gl phase ar rest and Annexin V-1"ITC stainìng, Furthermore‘ Bax expression in creased together with p53 and p21WAF1!CIPl, whìle the Bcl-2 expression decreased in the immortalized and malig nant keratinocytes treated with 01"0 , Time-dependent cytochrome c from mitochondria was observed in D1"O-treated [l-IOK and 0 1'머 cancel‘ ceJJ s, and was accompanied by the activation of caspase-3 in IHOK cells. These resu lts demonstrate that 0 1"0 has growth inhibitory effects on immortalized and malignant oral keratinocyLes Lhrough the induction of apoptosis and suggest that further evaluation of OFO as a potcntial thcrapcutic agent for human oral precancerous and cancerous lesions is warranted
        18.
        2004.04 KCI 등재 서비스 종료(열람 제한)
        Molecular genetic markers have wide applicability for a various genetic analyses, and genetic mapping with PCR-based markers has identified many loci in the rice genome. This study was conducted to develop a genetic map of rice based on SSR and MITE-AFLP