검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 212

        122.
        2004.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Ixeris dentata is a typical oriental herb. It is a widely distributed perennial in Korea, Japan and China, which belongs to the Compositae Family. The whole plant of I. dentata has been used for the treatment of pneumonia, contusion, tumor and hepatitis.
        4,000원
        123.
        2004.12 구독 인증기관 무료, 개인회원 유료
        Human embryonic stem (ES) cells are derived from the inner cell mass of the preimplantation embryo. Human ES cells have the capacity to differentiate into various types of cells in the body. Human ES cells are indefinite source of cells for cell therapy in various degenerative disorders including neuronal disorders. Directed differentiation of human ES cells is a prerequisite for their clinical application. The objective of this study is to develop the culture condition for the derivation of neural precursor cells from human ES cells. Neural precursor cells were derived from human ES cells in a stepwise culture condition. Neural precursor cells in the form of neural rosette structures developed into neurospheres when cultured in suspension. Suspension culture of neurospheres has been maintained over 4 months. Expressions of nestin, soxl, sox2, pax3 and pax6 transcripts were upregulated during differentiation into neural precursor cells by RT-PCR analysis. In contrast, expression of oct4 was dramatically downregulated in neural precursor cells. Immunocytochemical analyses of neural precursor cells demonstrated expression of nestin and SOX1. When induced to differentiate on an adhesive substrate, neuro-spheres were able to differentiate into three lineages of neural systems, including neurons, astrocytes and oligo-dendrocytes. Transcripts of sox1 and pax6 were downregulated during differentiation of neural precursor cells into neurons. In contrast, expression of map2ab was elevated in the differentiated cells, relative to those in neural precursor cells. Neurons derived from neural precursor cells expressed NCAM, Tuj1, MAP2ab, NeuN and NF200 in immunocytochemical analyses. Presence of astrocytes was confirmed by expression of GFAP immuno-cytochemically. Oligodendrocytes were also observed by positive immuno-reactivities against oligodendrocyte marker O1. Results of this study demonstrate that a stepwise culture condition is developed for the derivation of neural precursor cells from human ES cells.
        4,000원
        130.
        2020.12 KCI 등재 서비스 종료(열람 제한)
        High-quality and high-phytonutrient watermelon fruits have strong market opportunities besides their health related benefits. Hence, investigating quality and nutritional related traits of watermelon genetic resources could provide important baseline data in breeding for increased lycopene content thereby increasing the marketability of watermelon. To this end, we have examined some fruit morphological traits and lycopene content of 105 genetic resources. Seeds, originally obtained from 22+ countries, were obtained from the National Agrobiodiversity Center, Jeonju, South Korea, grown in an experimental field and harvested at a fully mature stage. The size of pistil scar (SPS), the width of stripes (WS), weight of fruit (WF), length of fruit (LF), width of fruit (WIF), the thickness of pericarp (TP), soluble solids content (SSC), fruit shape in longitudinal section, ground color of skin, the intensity of the green color of skin, fruit shape at the apical part, grooving distribution, conspicuousness of stripes, and main color of the flesh were recorded on the field and inside laboratory and the lycopene was measured using spectrophotometric and HPLC methods. Watermelon fruits have shown a diverse morphological characters. Red and pink fleshed fruits dominated in the entire collections. Fruits with higher thickness of rind were found to exhibit less soluble solid content (SSC). Korean origin fruits were characterized by intermediate SSC while the United States of America (USA), Russia (RUS), Tajikistan (TJK), Turkmenistan (TKM), Taiwan (TWN), and Uruguay (URY) originated fruits had the highest SSC. The lycopene content varied between 41.37 and 182.82 ㎍/g, 2.81 and 163.72 ㎍/g, and 3.54 and 255.47 ㎍/g using HPLC, UV-Vis spectrophotometer, and microplate reader spectrophotometer, respectively. Red- and pink-fleshed fruits had the highest levels of lycopene content compared to the yellow- and orange-fleshed. Lycopene content had a significant positive correlation with SSC, however, no correlations were detected between lycopene and other quantitative fruit morphological characters. Our study demonstrated high diversity exists in fruit morphological traits and lycopene content of the germplasm collections which provide beneficial baseline data for a future breeding program and utilization of watermelon germplasm collections in gene banks for the maintenance and improvement of the current levels of production, marketability, and health-related benefit of watermelon fruits.
        131.
        2020.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The Korean Institute of Technology Satellite (KITSAT-1) is the first satellite developed by the Satellite Technology Research Center and the University of Surrey. KITSAT-1 is orbiting the Earth’s orbit as space debris with a 1,320 km altitude after the planned mission. Due to its relatively small size and altitude, tracking the KITSAT-1 was a difficult task. In this research, we analyzed the tracking results of KITSAT-1 for one year using the Midland Space Radar (MSR) in Texas and the Poker Flat Incoherent Scatter Radar (PFISR) in Alaska operated by LeoLabs, Inc. The tracking results were analyzed on a weekly basis for MSR and PFISR. The observation was conducted by using both stations at an average frequency of 10 times per week. The overall corrected range measurements for MSR and PFISR by LeoLabs were under 50 m and 25 m, respectively. The ionospheric delay, the dominant error source, was confirmed with the International Reference of Ionosphere-16 model and Global Navigation Satellite System data. The weekly basis orbit determination results were compared with two-line element data. The comparison results were used to confirm the orbital consistency of the estimated orbits.
        132.
        2019.03 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The Optical Wide-field patroL-Network (OWL-Net) is a global optical network for Space Situational Awareness in Korea. The primary operational goal of the OWL-Net is to track Low Earth Orbit (LEO) satellites operated by Korea and to monitor the Geostationary Earth Orbit (GEO) region near the Korean peninsula. To obtain dense measurements on LEO tracking, the chopper system was adopted in the OWL-Net’s back-end system. Dozens of angle-only measurements can be obtained for a single shot with the observation mode for LEO tracking. In previous work, the reduction process of the LEO tracking data was presented, along with the mechanical specification of the back-end system of the OWL-Net. In this research, we describe an integrity assessment method of time-position matching and verification of results from real observations of LEO satellites. The change rate of the angle of each streak in the shot was checked to assess the results of the matching process. The time error due to the chopper rotation motion was corrected after re-matching of time and position. The corrected measurements were compared with the simulated observation data, which were taken from the Consolidated Prediction File from the International Laser Ranging Service. The comparison results are presented in the In-track and Cross-track frame.
        133.
        2018.09 KCI 등재 서비스 종료(열람 제한)
        Angelica tenuissima, also known as Ligusticum tenuissimum, is classified as a food-related plant and has been used as traditional medicines treating headache and anemia in Asia. However, its anti-melanogenic effect has not been reported in detail. When the extract of Angelica tenuissima (ATE) was prepared by the extraction with 70% EtOH at 80°C (final yield = 22%), the contents of decursin and Z-ligustilide in ATE were determined 0.06% and 8.43%, respectively. Total flavonoid and phenolic content in mg ATE were 5.52±0.07 ㎍ quercetin equivalents and 237.27±13.24 ㎍ gallic acid equivalents, respectively. Antioxidant capacity of ATE determined by DPPH and ABTS assay was increased with a dose dependent manner up to 1000 ㎍/㎖. The amount of melanin synthesis followed by α-melanocyte stimulating hormone on B16F10 cells were significantly reduced in the presence of ATE (250 to 1000 ㎍/㎖, p<0.05). ATE (125 to 1000 ㎍/㎖, p<0.05) suppressed the tyrosinase activity but did not show any significant effect on α-glucosidase activity at the same condition. Taken together, ATE possesses tyrosinase inhibitory potential with significant antioxidant capacities. These effects of ATE might be involved in suppression of melanin synthesis, at least, in B16F10 cells. The anti-melanogenic potential of ATE will provide an insight into developing a new skin whitening product.
        134.
        2017.10 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to investigate the effects of rooting promoters on rooting and seedling quality in Buddleja davidii ‘Empire Blue’, Hydrangea paniculata ‘Magical Candle’, Hydrangea arborescence ‘Annabelle’, Stephanandra incisa semi-hardwood cuttings. IAA and IBA (500, 1000, or 1500 mg・L-1 soaking for 30 minutes and 3,000 mg・L-1 dipping for 10 seconds) or RootoneTM were used as rooting promoter. In B. davidii ‘Empire Blue’, IBA 1,500 mg・L-1 soaking reduced rooting percentage than control, but the effect of rooting promoters was generally insignificant. Number of leaves and shoot length were reduced in RootoneTM and IBA 1,500, 3,000 mg・L-1 treatments. IAA 1,000~3,000 mg・L-1 and IBA 500 mg・L-1 treatments showed better mat formation than control. The rooting ratio of H. paniculata ‘Magical Candle’ increased to 66.7% in IBA 1,500 mg・L-1 soaking treatment compared with 26.4% in the control. The mat formation was higher in RootoneTM, IAA and IBA treatments compared to control, and root length showed longer tendency in IAA and IBA except RootoneTM. The rooting ratio of H. arborescence ‘Annabelle’ was highest at 70.8% in the control and auxin treatments showed negative effect on the rooting percentage except IAA 1,000 mg・L-1 soaking treatment. The mat formation was very poor in IBA 1,000 and 1,500 mg・L-1 soaking at 1.1 and 1.3, respectively. S. incisa showed high rooting percentage at RootoneTM (80%) and IAA 1,500 mg・L-1 (80%) treatments compared to control (51.7%). Root length and dry weight were high in IAA 1,500 mg・L-1 soaking treatment. As a result, B. davidii ‘Empire Blue’ and H. arborescence ‘Annabelle’ did not need rooting promoter for stem cuttings, and IBA 1,500 mg・L-1, IAA 1,500 mg・L-1 soaking treaments could be used to improve rooting and seedling quality of H. paniculata ‘Magical Candle’ and S. incisa semi-hardwood cuttings, respectively.
        135.
        2017.06 KCI 등재 서비스 종료(열람 제한)
        EP was obtained through 20% ethanol extraction of Pueraria lobata root, and the fermented form of EP, FEP, was prepared from the EP after incubating with Lactobacillus rhamnosus vitaP1. There was no significant toxicity by EP and FEP up to 1000 ㎍/㎖ in NIH-3T3, HaCaT, and B16F10 cells. In addition to antioxidant potentials of EP and FEP determined by DPPH and ABST assays, we confirmed increase of procollagen type I and elastin synthesis by supplementation of the EP and FEP at the concentration of 50 ㎍/㎖ using ELISA kits. The protein expression levels of matrix metalloprotease (MMP)-1, -3, and -9, those are involved in the degradation of collagen or other skin matrix proteins, were remarkably suppressed while their inhibitory protein metallopeptidase inhibitor 1 (TIMP-1) was greatly up-regulated by supplementation of the EP and FEP at a concentration of 50 ㎍/㎖. Taken together, both EP and FEP supplementation could be involved in the suppression of the skin wrinkle formation through inhibiting degradation of collagen and stimulating the synthesis of collagen and elastin. The results showed that the anti-wrinkle potential of the EP and FEP will be a promising candidate for developing cosmeceutical compounds or products.
        136.
        2017.02 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        본 연구는 절임배추의 유통 중 단기 유통시스템에 따른 이화학적 및 미생물학적 품질 변화에 대하여 알아보고, 그에 따른 품질지표를 평가하고자 실시하였다. 여름철에 제조한 절임배추는 탈수 후 바로 저밀도 폴리에틸렌 필름에 포장하거나 2% 염수와 함께 포장하여 실온유통시스템(conventional system)과 저온유통시스템(cold-chain system)을 갖춘 1톤 트럭에 각각 구분하여 적재하였으며 약 6시간동안 유통하였다. 이화학적 및 미생물학적 변화로 품온, 염도, 산도, pH, 수분감, 일반세균, 젖산균, 대장균, 대장균군, 효모 및 곰팡이에 대해 조사하였다. 실온유통시스템의 경우 절임배추의 품온은 필름 내 염수포장 절임배추에서 19.57℃, 필름포장 절임배추에서 19.43℃, 저온유통시스템의 경우 필름 내 염수포장 절임배추에서 10.73℃, 필름포장 절임배추에서 12.90℃까지 증가하였다. 염도변화는 저온유통시스템의 경우 변화가 없었으나, 실온유통시스템의 경우 필름 내 염수포장 절임배추와 필름포장 절임배추에서 품온과 각각의 염도변화가 정의 상관성을 보이며 초기에 비해 1.2배 혹은 1.7배 더 높았다. 산도는 저온유통시스템에서 두 가지 포장조건 모두 약간 증가하였다. 실온유통시스템에서 필름 내 염수포장 절임배추의 총 호기성균과 젖산균수가 각각 7.62 log CFU/g 및 6.77 log CFU/g까지 증가하는 동안 필름포장 절임배추는 각각 5.62-5.85 log CFU/g과 4.33-4.83 log CFU/g의 범위를 나타냈다. 그러나 저온유통시스템의 경우 유통시간 증가에 따른 유의미한 미생물학적 변화를 보이지 않았다. 따라서 절임배추 유통 시 저온유통시스템을 이용한 경우 이화학적 품질 유지 및 미생물 제어에 효과적이며, 실온유통시스템을 이용한 경우 품온 상승에 따른 염도 및 미생물 변화에 유의해야 한다. 또한 염도, 총호기성균 및 젖산균은 실온유통시스템 내 품질지표로 이용가능하며, 산도는 저온유통시스템 내 품질지표로 이용가능하다.
        137.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        The purpose of this study was to investigate the improvement of growth in Israeli carp (Cyprinus carpio), and the cross experiment was carried out with two strains of Israeli carp. Four combinations of Israeli carp from Jeonbuk fisheries farm and Songpu mirror carp from Heilong Jiang, China (KK; Jeonbuk ♀ × Jeonbuk ♂, KC; Jeonbuk ♀ × China ♂, CC; China ♀ × China ♂ and CK; China ♀ × Jeonbuk ♂) were developed and reared. Body length, body weight and condition factor were determined at 20, 40, 60 and 170 days post-hatch (DPH). The results showed that there were differences in growth rate of the four groups. Body length of four groups were CK > CC > KC > KK and body weight were CC > CK > KC > KK at 170 DPH. The growth perfomance of four groups were statistically significant difference (P<0.05). During the rearing, CC group had longer length and higher weight at 170 DPH compared to other three groups and also condition factor was highest in the CC group, but there was no significant difference in a survival rate. These results indicated that the growth performance mainly depended upon brooder combination but survival rate could not significantly affect brooder.
        138.
        2016.10 서비스 종료(열람 제한)
        Background : Korean Indigenous Hylotelephium erythrostictum is widely distributed in South Korea and is used in Korean traditional medicine. In this study, the phylogenetic analysis of Korean native Hylotelephium erythrostictum and related plants on Internal Transcribed Spacer (ITS) sequences were investigated to distinguish its origin. Methods and Results : The phylogenetic analysis of 6 species of Hylotelephium were investigated by ITS. The dendrogram was constructed by UPGMA(Unweighted Pair Group Method with Arithmetic Mean) clustering algorithm based on genetic similarity of ITS. In the ITS sequence analysis, the size of total was varied from 676 to 779 bp. The size of ITS 1 was rated at 287bp, while ITS 2 was rated at 123bp. The G+C content of ITS region was ranged from 60 to 66%. In the ITS tree, six species of Hylotelephium were monophyletic, and H. viviparum was the first branching within the clade. Conclusion : H. spectabile formed a clade with H. erythrostictum, while H. verticillatum formed with H. viviparum.
        139.
        2016.10 서비스 종료(열람 제한)
        Background : Gentinae Macrophyllae Radix is one of the traditional medicines originated from the roots of multiple plants, Gentiana macrophylla Pall., Gentiana straminea Maxim., Gentiana crassicaulis Duthie ex Burkill and Gentiana dahurica Fisch., in Gentianaceae. Multi-origin traditional medicine usually has adulteration problem based on the morphological similarity and/or misunderstanding the species. Therefore, accurate and reliable identification criteria to ensure drug safety and quality is necessary. Methods and Results : We collected four original species of Gentinae Macrophyllae Radix from plantations and markets in China and Korea. DNA barcoding with four barcoding markers (Internal Transcribed Spacer (ITS), rbcL, trnL intron, trnL-F intergenic sapcer) was performed. Intra-specific variation was observed in ITS nucleotide sequence however, successfully distinct four original species based on the nucleotide discrepancy while trnL intron has no difference. trnL-F intergenic spacer has two transitions(T→C and A→G) sites only in G. crassicaulis and rbcL shows one transition(C→T) site in G. dahurica and G. macrophylla. Phylogenetic relationship analysis of the Gentinae Macrophyllae Radix revealed two major clades – clade I including three groups, G. macrophylla, G. straminea and G. dahurica, and clade II including G. crassicaulis. This aspects was shown more clear with multi-region combined analysis. Conclusion : DNA barcoding will be accurate and powerful criteria for the analysis the origin of Gentinae Macrophyllae Radix. However, single region analysis might be deficient such as trnL intron, rbcL and trnL-F intergenic spacer results in this research. Multi-region combined analysis based on the multiregional DNA barcode markers will be overcome the disadvantage and also increase the precision.
        140.
        2016.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        As described in the previous paper (Park et al. 2013), the detector subsystem of optical wide-field patrol (OWL) provides many observational data points of a single artificial satellite or space debris in the form of small streaks, using a chopper system and a time tagger. The position and the corresponding time data are matched assuming that the length of a streak on the CCD frame is proportional to the time duration of the exposure during which the chopper blades do not obscure the CCD window. In the previous study, however, the length was measured using the diagonal of the rectangle of the image area containing the streak; the results were quite ambiguous and inaccurate, allowing possible matching error of positions and time data. Furthermore, because only one (position, time) data point is created from one streak, the efficiency of the observation decreases. To define the length of a streak correctly, it is important to locate the endpoints of a streak. In this paper, a method using a differential convolution mask pattern is tested. This method can be used to obtain the positions where the pixel values are changed sharply. These endpoints can be regarded as directly detected positional data, and the number of data points is doubled by this result.