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        검색결과 107

        61.
        2012.03 구독 인증기관 무료, 개인회원 유료
        Suspension culture is a useful tool for culturing embryonic stem (ES) cells in large-scale, but the stability of pluripotency and karyotype has to be maintained in vitro for clinical application. Therefore, we investigated whether the chromosomal abnormality of ES cells was induced in suspension culture or not. The ES cells were cultured in suspension as a form of aggregate with or without mouse embryonic fibroblasts (MEFs), and 0 or 1,000 U/ml leukemia inhibitory factor (LIF) was treated to suspended ES cells. After culturing ES cells in suspension, their karyotype, DNA content, and properties of pluripotency and differentiation were evaluated. As a result, the formation of tetraploid ES cell population was significantly increased in suspension culture in which ES cells were co-cultured with both MEFs and LIF. Tetraploid ES cell population was also generated when ES cells were cultured alone in suspension regardless of the existence of LIF. On the other hand, the formation of tetraploid ES cell population was not detected in LIF-free condition, in which MEFs were included. The origin of tetraploid ES cell population was turned out to be E14 ES cells and not MEFs by microsatellite analysis and the basic properties of them were still maintained despite ploidy-conversion to tetraploidy. Furthermore, we identified the ploidy shift from tetraploidy to near-triploidy as tetraploid ES cells were differentiated spontaneously. From these results, we demonstrated that suspension culture system could induce ploidy-conversion generating tetraploid ES cell population. Moreover, optimization of suspension culture system may make possible mass-production of ES cells.
        4,000원
        62.
        2011.09 구독 인증기관 무료, 개인회원 유료
        In the present study, total methanol extracts prepared from Alpinia katsumadai showed significant protective effects against the oxidative stress induced by hydrogen peroxide, UV-C or γ-ray irradiation. These protective effects were substantially increased by treatment with 20~100 μg/ml of the extract. The A. katsumadai total methanol preparation was further fractionated into n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these five fractions, the ethylacetate and butanol fractions of A. katsumadai showed the strongest protective effects against oxidative stress induced by UV-C and γ-ray irradiation. These fractions also showed high DPPH radical scavenging and lipid peroxidation inhibitory activities. In addition, both fractions displayed cell proliferation activation effects, as evidenced by significant increases in colony formation. Our current data thus suggest that the mechanisms underlying the protective effects of A. katsumadai against oxidative damage may include radical scavenging, protection against cell membrane damage and stimulation of cell proliferation.
        4,000원
        66.
        2010.12 구독 인증기관 무료, 개인회원 유료
        In our present study, we investigated the effects of continentalic acid on Streptococcus mutans (S. mutans) biofilm. Methanol extract of Aralia continentalis (A. continentalis) was suspended in water and sequentially partitioned with CHCl3, ethyl acetate (EtOAc), and n-butanol (n-BuOH). The CHCl3 fraction showed the highest activity and an antibacterial compound against S. mutans was isolated from this preparation through various chromatography methods by bioassay guided fractionation. MS, 1H - NMR and 13C-NMR analysis showed that the active principle was continentalic acid which was confirmed to show significant inhibitory effects against S. mutans biofilm. These results may provide some scientific rationale for the traditional use these extracts for the treatment of dental diseases.
        4,000원
        67.
        2010.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The purpose of this study was to identify the effects of manipulation on the velocity of cerebral blood flow and level of pain in cervicogeinc headache patients. The velocity of cerebral blood flow of 30 cervicogeinc headache patients(male=15, female=15, age=24.00±3.60) and 33 normal subjects(male=15, female=18, age=23.27±3.00) was compared. The 30 cervicogeinc headache patients were divided into suboccipitalis relaxation group, cervical manipulation group, and placebo group, and each were given different interventions. The velocity of cerebral blood flow and pain level was measured before intervention, and 1, 2, 3 weeks after intervention. The velocity of cerebral blood flow was measured with the Transcranial Doppler(TCD), and pain level was measured with visual analog scale(VAS). Blood flow velocity of middle cerebral artery in cervicogeinc headache patients was slower than those in healthy subjects. Physical therapy intervention did not have significant effect on velocity of cerebral blood flow, but slowly decreased at intervention for pain level increased. The suboccipitalis relaxation group and cervical manipulation group showed significant effect in decreasing pain level compared to the placebo group(p<.05). Directly applied manipulation therapy in the neck area not only has effect on joint of cervical and soft tissue but also on blood vessels and nerves which pass the neck area, and because of those results of manual therapy seems to help recovery.
        4,000원
        68.
        2010.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        국화는 개화를 위해서는 30일의 지속적인 단일 처리가 요구되는 원예작물인데 본 연구에서는 국화의 화형별 홑꽃 타입의 ‘Limelight’, ‘Sunlight’, ‘Candle Light’, ‘Firebrand’, ‘Twilight’와 겹꽃 타입의 ‘Spirit’, ‘Sunburst Spirit’, ‘Mandalay’, ‘Illini Harvest’가 단일 (SD)−장일 (LD)−단일 (SD)의 일장 처리가 생장 및 개화조절 반응에 미치는 효과를 알아보고자 수행되었다. 30일간의 단일 처리와 5일 또는 10일 동안의 장일처리 후 5일 또는 10일 동안의 단일조건을 각각 처리하였다. 품종별 차이는 없었으나 5 SD−10 LD−25 SD 처리는 개화를 지연 시키고 설상화 수가 증가되었다. 특히 ‘Firebrand’와 ‘Candlelight’ 품종의 설상화 수는 각각 40개와 60.8개로 대조구에 비해 현저히 증가되었다. 또한 SD−LD−SD 처리는 개화를 6일에서 7일정도 지연시키는 것 외에는 큰 효과를 나타나지 않았다. 그러나 ‘Illini Harvest’와 ‘Limelight’의 설상화 수는 어떤 SD−LD−SD 처리에 의해서도 증가되지 않았다. 따라서 추후 새로운 품종별 일장처리에 따른 추가적인 연구 분석이 뒤따라야 할 것으로 판단되며 본 연구 결과는 국화의 신품종 육성을 위한 자료에 유용함을 알 수 있었다.
        4,000원
        72.
        2008.12 구독 인증기관 무료, 개인회원 유료
        The present study reports the protective properties of a total methanol extract of B. platyphylla var. japonica against ultraviolet (UV)-C irradiation. Pretreatment of Chinese hamster fibroblast (V79-4) cells with a total methanol extract significantly increased cell survival following 300J/m² of UV-C irradiation. The total methanol extract was further fractionated into 5 fractions: n-hexane, dichloromethane, ethylacetate, n-butanol and water fractions. Among these fractions, B. platyphylla var. japonica ethylacetate, butanol and water fractions showed significant protective effects against the cellular damage induced by UV-C irradiation. In order to elucidate the mechanism underlying this protective effect, DPPH (Editor note: abbreviations should be spelled out at first use.) radical scavenging and lipid peroxidation inhibitory activity were measured. Significant radical scavenging and lipid peroxidation inhibitory activities were observed for the ethylacetate fraction. In summary, the present data demonstrate that an extract of B. platyphylla var. japonica has a significant protective effect against UV-C irradiation. The underlying mechanism of this protective effect may involve radical scavenging and inhibition of lipid peroxidation by the B. platyphylla var. japonica extract.
        4,000원
        73.
        2008.12 구독 인증기관 무료, 개인회원 유료
        Inositol 1,4,5-trisphosphate (IP₃) plays an important role in the release of Cα²+ from intracellular stores into the cytoplasm in a variety of cell types. IP₃ translocation dynamics have been studied in response to many types of cell signals. However, the dynamics of cytosolic IP₃ in salivary acinar cells are unclear. A green fluorescent protein (GFP)-tagged pleckstrin homology domain (PHD) was constructed and introduced into a phospholipase C δ1 (PLC δ1) transgenic mouse, and then the salivary acinar cells were isolated. GFP-PHD was heterogeneously localized at the plasma membrane and intracellular organelles in submandibular gland and parotid gland cells. Application of trypsin, a G protein-coupled receptor activator, to the two types of cells caused an increase in GFP fluorescence in the cell cytoplasm. The observed time course of trypsin-evoked IP₃movement in acinar cells was independent of cell polarity, and the fluorescent label showed an immediate increase throughout the cells. These results suggest that GFP-PHD in many tissues of transgenic mice, including non-cultured primary cells, can be used as a model for examination of IP₃intracellular dynamics.
        4,000원
        74.
        2007.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        분리층 두께가 5 μm이며 Si/Al 몰비가 1.5인 Na형 faujasite 제올라이트 분리막을 이차성장 공정에 의하여 제조하였고, 투과부에 13X 제올라이트 흡착제 충진 전후의 진공모드에서의 CO2/N2 분리거동을 CO2/N2 몰비가 1인 혼합기체에 대하여 30℃에서 평가하였다. 충진된 13X 제올라이트 흡착제는 CO2 투과도와 CO2/N2 선택도를 동시에 증진시켰다. 이 현상은 13X 제올라이트 흡착제 충진이 다공성 α-알루미나 지지체의 기공채널을 통한 CO2 탈출을 증진시킴으로써 faujasite 제올라이트/α-알루미나 상계면에서의 CO2 탈착을 증진시켰기 때문으로 설명되었다. 본 논문으로부터 흡착제와 분리막의 혼성화는 일반적으로 보여지는 선택도와 투과도의 역비례 관계를 획기적으로 개선할 방법임이 확인되었다.
        4,000원
        76.
        2018.10 KCI 등재 서비스 종료(열람 제한)
        Fruit trees are a key part of agriculture in rural areas and have recently been a part of ecotourism or agrotourism. This study analyzes user segmentation based on user motivation to determine characteristics of potential customers in fruit tree farms, and thereby develop fruit tree experience and educational programs. We conducted a survey of 253 potential customers of fruit tree experience programs in September 2017. Data were evaluated using factor and cluster analyses. The results of the cluster analysis identified four distinct segments based on potential customers' motivations, that is, activity-oriented, learning-oriented, leisure-oriented, and purchase-oriented. These clusters showed that significant differences in the preference of potential customers exist. Different markets were segmented based on the benefits sought by users. The segments’ characteristics were identified and activities relevant to each segment were proposed for rural tourism. Lastly, this study suggests directions for development of fruit tree farm experience and educational programs.
        77.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to apply a horticultural therapy program to childhood cancer patients, to analyze their psychosocial changes and thus to examine its possibility as a way to manage the recovery of childhood cancer patients. This study was conducted on patients who were diagnosed with childhood cancer, and they were divided into the experimental group (8 patients who visited H association offices located in 3 cities and participated in the horticultural program) and the control group (5 patients who did not participate in the program). The homogeneity between the two groups before conducting the program was compared, and there was no statistically significant difference, which proved that the two groups were homogeneous. After conducting the program, the score of social immaturity, one of the sub-categories of problem behaviors, of the experimental group was statistically significantly lower than that of the control group (p=.019). Changes before and after the program within the groups were compared, and the somatization score (p=.039) of the experimental group (p=.039) after the program was 1.13, down from 2.13 before the program. The social immaturity score (p=.017) of the experimental group after the program was 1.00, down from 2.63 before the program, and the attention problem score (p=.026) of the group after the program was 1.25, down from 2.50 before the program. The total problem behavior score (p=.034) of the experimental group after the program was 9.63, down from 18.50 before the program, showing a statistically significant decrease. The cumulative subjective mood score (p=.000) of the experimental group throughout the entire sessions after the program was 7.82, up from 6.99 before the program, showing a statistically significant increase. Therefore, it can be concluded that the horticultural therapy program developed based on the ‘relaxationsocial support-cognitive behavior’ strategy was effective to reduce the negative psychosocial state of childhood cancer patients.
        78.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        Polyploidy is occurred by the process of endomitosis or cell fusion and usually represent terminally differentiated stage. Their effects on the developmental process were mainly investigated in the amphibian and fishes, and only observed in some rodents as mammalian model. Recently, we have established tetraploidy somatic cell nuclear transfer-derived human embryonic stem cells (SCNT-hESCs) and examined whether it could be available as a research model for the polyploidy cells existed in the human tissues. Two tetraploid hESC lines were artificially acquired by reintroduction of remained 1st polar body during the establishment of SCNT-hESC using MII oocytes obtained from female donors and dermal fibroblasts (DFB) from a 35-year-old adult male. These tetraploid SCNT-hESC lines (CHA-NT1 and CHA-NT3) were identified by the cytogenetic genotyping (91, XXXY,-6, t[2:6] / 92,XXXY,-12,+20) and have shown of indefinite proliferation, but slow speed when compared to euploid SCNT-hESCs. Using the eight Short Tendem Repeat (STR) markers, it was confirmed that both CHA-NT1 and CHA-NT3 lines contain both nuclear and oocyte donor genotypes. These hESCs expressed pluripotency markers and their embryoid bodies (EB) also expressed markers of the three embryonic germ layers and formed teratoma after transplantation into immune deficient mice. This study showed that tetraploidy does not affect the activities of proliferation and differentiation in SCNT-hESC. Therefore, tetraploid hESC lines established after SCNT procedure could be differentiated into various types of cells and could be an useful model for the study of the polyploidy cells in the tissues.
        79.
        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.
        80.
        2016.10 서비스 종료(열람 제한)
        Background : This study was carried out to survey the effect of IBA (indole-3-butric acid) concentration on root development characteristics in Viburnum dilatatum cuttings. Methods and Results : The cuttings were collected on July 28, 2016 from plants growing in Korea National Arboretum. Cuttings were treated with different IBA concentrations [0 (control), 10, 100, 1000, 2000 ㎎⋅L-¹] for 10 seconds. Rooting parameters (root number, the longest root length, root fresh weight, root dry weight, rooting percentage, and survival rate) were observed at 8 weeks after cuttings. Rooting percentage was 43, 33, 17, 47, and 40 % at 0, 10, 100, 1000, and 2000 ㎎⋅L-¹ of IBA, respectively. Root number (13.4) was highest under 1000 ㎎⋅L-¹ IBA. Root length (9.4 ㎝) and Root weight (fresh and dry) were highest under 1000 ㎎⋅L-¹ IBA. Conclusion : According to the results, 1000 ㎎⋅L-¹ IBA was the best treatment for increasing percentage rooting percentage and other root development characteristics of V. dilatatum cuttings.
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