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        검색결과 56

        21.
        2015.07 구독 인증기관 무료, 개인회원 유료
        In establishing and overseeing ASIAPARC Federation in March of 2016 in Jeju Island Korea, it will be essential for us to learn aspiration, network, purpose, values, goals and strategies from 42 years experiences of EUROPARC Federation as our partnership organization such as practicing exchange programs and joint conferences. We also believe we can add one more principle, ‘Initiating Island Resilience’, into the three principles of the Jeju Declaration of 1) Scaling up Conservation, 2) Nature-based Solutions, and 3) Sustainability in Action through the opening of a "Green Growth Organization" of the Jeju Declaration of WCC 2012.
        4,000원
        22.
        2012.06 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 말단기에 diene 기와 dithiol 기를 갖는 두 가지 새로운 액정 단량체의 합성을 보고하며, 이를 배향 후 광경화하여 광학 위상지연 필름을 제조하는 방법에 대해 논의하였다. 특히 합성된 두 가지액정단량체의 구조를 확인하였으며, 이들의 액정특성을 연구하였다. 또한 이들을 광개시제와 혼합하여광경화형 액정조성물을 제조하고 이를 러빙 배향막이 코팅된 표면 위에서배향시킨 후 광조사하여 thiol-ene 중합에 의해 경화함으로써 광학 위상지연 필름을 제조하였다.
        4,000원
        23.
        2007.09 구독 인증기관 무료, 개인회원 유료
        Thiol-ene 중합이 가능한 새로운 반응성 액정 단량체로서 2,5-bis[4'-(5-hexenyloxy) benzoyloxy]toluene를 합성하였다. 반응성 액정 단량체는 ethyl 4-hydroxybenzoate와 6-bromo-1-hexene을 반응하여 얻은 중간체인 4'-(5-hexenyloxy)benzoic acid와 methyl hydroquinone를 축합하여 79%의 수율로 합성하였다. 얻어진 반응성 액정 단량체의 구조는 1H-NMR과 FT-IR을 이용하여 확인하였으며, DSC와 온도 조절기가 부착된 편광현미경을 이용하여 관찰한 결과 65℃와 157℃ 사이에서 네마틱 액정상을 보임을 확인하였다. 반응성 액정 단량체는 1,6-hexanethiol, 광개시제와 함께 혼합하여 thiol-ene 중합을 위한 광중합 조성물을 제조하였다. 러빙 처리된 폴리이미드 기판 상에서 이와 같은 조성물을 코팅한 후 광조사에 의해 중합한 결과 λ/4의 위상차를 갖는 광학보상 필름을 제조할 수 있었다.
        4,000원
        26.
        2001.09 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        The molecular cloud associated with the H II region S301 has been mapped in the J = 1-0 transitions of 12CO and 13CO using the 13.7 m radio telescope of Taeduk Radio Astronomy Observatory. The cloud is elongated along the north-south direction with two strong emission components facing the H II region. Its total mass is 8.7 × 10 3 M⊙. We find a velocity gradient of the molecular gas near the interface with the optical H II region, which may be a signature of interaction between the molecular cloud and the H II region. Spectra of CO, CS, and HCO+ exhibit line splitting even in the densest part of the cloud and suggests the clumpy structure. The radio continuum maps show that the ionzed gas is distributed with some asymmetry and the eastern part of the H II region is obscured by the molecular cloud. We propose that the S301 H II region is at the late stage of the champagne phase, but the second generation of stars has not yet been formed in the postshock layer.
        4,000원
        27.
        2017.09 KCI 등재 서비스 종료(열람 제한)
        Present study aimed to determine the effect of ‘bitter melon’, a popularly used fruit in Bangladesh and several other Asian countries, on high-fat-diet-induced type 2 diabetes. To investigate the effect, ethanol extract from bitter melon (BME) as a dietary supplement with mouse chow was used. BME was found to significantly attenuate the high-fat diet (HFD) -induced body weight and total fat mass. BME also effectively reduced the insulin resistance induced by the HFD. Furthermore, dietary supplementation of BME was highly effective in increasing insulin sensitivity and reducing hepatic fat and obesity. These results indicate that BME could be effective in attenuating type 2 diabetes and could therefore be a preventive measure against type 2 diabetes.
        28.
        2015.07 서비스 종료(열람 제한)
        Space has many distinguishable characteristics from earth such as strong cosmic radiation, microgravity, supervaccum and weak magnetic field. For this reason, space environments can be used an efficient mutagen for plant breeding nowadays. To identify the affected genes by condition in space with outer space, Brachypodium seeds were placed in the Russia Segment (RS) Biorisk module of International Space Station (ISS). Brachypodium distachyon is a model system for temperature grass, because they represent the characteristics for annual winter grass. Seeds and organs of plants carried by satellite or spacecraft to space can be genetically mutated by exposing space environment. We performed a duplicated RNA sequencing to profile the differentially expressed genes. As a results, about 700 genes were upregulated and 250 genes were downregulated by cosmic environments, respectively. In the molecular function category, protein kinase and transcription activity related genes were upregulated. Among the many transcription factors (TFs), stress related TFs such as ERF, NAC and WRKY were differentially expressed in space exposed samples. In the future, their expression will be identified by using qRT_PCR.
        29.
        2015.07 서비스 종료(열람 제한)
        This study was carried out to determine the amount of lignin, cellulose, and hemicellulose in six kenaf cultivars during different harvesting stages. Three mutant cultivars (Jangdae, Jeokbong and Baekma), two original cultivars (Jinju, C14), and one Chinese cultivar (Auxu) were planted on May 14, 2013. Four harvesting times were made at intervals of 20 days from 15 July to 16 September, 2013. The overall growth characters of mutant cultivar ‘Jeokbong’ such as plant height, stem diameter, flowering time, and dry mass were similar with those of the original variety. The mutant cultivar ‘Baekma’ occurred 10-day late flowering in comparison with the original variety and also displayed higher dry mass than the original variety. Jinju, Auxu and Jangdae, mid-late maturing kenaf cultivars, had high dry weight compared to early maturing cultivars such as Jeokbong, Baekma and C14. In all cultivars, the lignin contents were increased by a late harvest. The Mid-late maturing kenaf cultivars showed high lignin content in comparison with those of the early maturity cultivars. There were no significant differences of cellulose, and hemicellulose content between the cultivars, however cellulose content in stems of these kenaf cultivars were significantly decreased by a late harvest. These results may provide valuable information to assist the parental selection of kenaf breeding.
        30.
        2015.07 서비스 종료(열람 제한)
        Rose (Rosa Hybrida Hort.) are of a high symbolic value and a great cultural importance in different societies. They are widely used as garden ornamental plants and as cut flowers. For the induction of mutation, gamma-rays are widely used as a mutagen. This study was carried out to establish a system for mutation breeding by irradiation of gamma-ray in rose. The rooted cuttings of five cultivar roses (Lovelydia, Vital, Aqua, Yellowbabe and Haetsal) are grown by in a greenhouse. They were two difference treatment (Before rooting gamma-ray irradiation, After rooting gamma-ray irradiation) were exposed to dose of 70 Gy using a 60Co gamma-irradiator (150 TBq of capacity ; ACEL, Canada) at the Korea Atomic Energy Research Institute. The irradiated plants were planted in a greenhouse, and investigated survival rate, mutation rate, flower buds number, and shoot length were planted after 80days. The two treatments of and growth characters was significantly reduced to 20% to 40% compared with the control. In addition, survival rate and mutation rate were ‘after rooting γ-ray irradiation (37.4~67.3% and 0.5~5.6%)’ higher than ‘before rooting γ-ray irradiation (18.3~50.8% and 0.3~3.4%)’. Mutation types were solid type, chimeric and mosaic petal mutants with various colors were induced from five rose. These results indicate that efficiency of mutation induction in rose by gamma-ray irradiation on petal colors and petal shapes in two difference treatment with rooted cutting system.
        31.
        2015.07 서비스 종료(열람 제한)
        Kenaf (Hibiscus cannabinus L.) native to Africa can be used as fiber, food, feedstock and bio plastic. This study was carried out to evaluate the mineral, amino acid and vitamin contents of six selected kenaf cultivars which are enable to produce seed under Korean circumstance. The leaves of three mutant cultivars (Jangdae, Jeokbong and Baekma), two original cultivars (Jinju, C14) and one Chinese cultivar (Auxu) were harvested at flowering time. Mineral components of kenaf leaves, such as calcium, potassium, and mineral, did not showed significant differences among the cultivars. As major amino acids including proline and phenylalanine, significant differences were found in these kenaf cultivars. The Auxu cultivar contained the highest amount of essential amino acid (Phenylalanine, Leucine, Isoleucine, Valine, Methionine and Lysine). The amount of vitamin displayed significant differences such as vitamin E and vitamin K among these cultivars. Especially, Jangdae cultivar contained the highest amount of vitamin E and vitamin K. Thus, these data suggested that Jangdae and Auxu is the most desirable cultivar containing high amount of vitamin and amino acid.
        32.
        2014.07 서비스 종료(열람 제한)
        Radiation technologies have been widely used in mutation breeding of crops. Although gamma-radiation has been predominantly applied in radiation breeding, ion beam irradiation is recently emerging as a methodology highly effective in induction of mutations that are useful for plant breeding. Therefore, we investigated the biological effects caused by irradiation of two types of ion beams, which were proton and ion beams, respectively, in pepper. In the evaluation of survival rate, LD50 values were between 300 and 350 Gy, 30 and 40 Gy in irradiation of proton and carbon beams, respectively, while LD50 for gamma-ray was determined to be between 50 and 100 Gy. Growth traits including shoot length, root length, and root width were also examined in pepper seedlings according to does of proton and carbon ion beams to estimate biological effectiveness of each radiation. The result was applied in the construction of pepper mutant population which will be used to develop pepper breeding materials containing novel characteristics.
        33.
        2014.07 서비스 종료(열람 제한)
        This study was conducted to determine the optimal dose of gamma-ray for mutation breeding in sorghum (Sorghum bicolor M.). Gamma-rays irradiated to dry seeds with various doses (0 to 1000 Gy) at Korea Atomic Energy Research Institute. Lethal dosage (LD50) was approximately 256 Gy. Significant decreases in growth characteristics (plant height, tiller number and fresh weight) were observed by dose of increased over 300 Gy. Reduction doses (RD50) was approximately 363 Gy in plant height. We also conducted comet assay to observe nucleus DNA damage due to gamma irradiation. In comet assay, a clear difference was identified over 100 Gy treatments. With increasing doses of gamma-ray in the range of 100 to 400 Gy, the rate of head DNA was decreased significantly from 93.52% to 67.57%. The most of the Sorghum cells were severely damaged in the integrity of DNA by gamma-ray. These data provide valuable information when the optimal dose should be chosen for purpose of mutation breeding program of Sorghum.
        34.
        2014.07 서비스 종료(열람 제한)
        This study was carried out to determine the effects of different harvesting stage on nutritive value and the quality of ensiled kenaf after fermentation among six kenaf cultivars. Six kenaf cultivars including two different maturity groups, mid-late maturing (Auxu, Jangdae and Jinju) and early-maturing (Baekma, Jeokbong and C14), were planted on May 14, 2013. Four harvesting times were made at intervals of 20 days from 15 July to 16 September, 2013. In all cultivars, the CP (crude protein) contents were decreased by a delayed harvest; the CP contents of kenaf silage were ranged from 92 to 184 g kg-1. Interestingly, there were no significant difference of NDF (neutral detergent fiber) and ADF (acid detergent fiber) content between the cultivars, however NDF and ADF content of kenaf silage were significantly increased by a late harvest. The silages of all cultivars displayed a low pH ranges less than 4.0, which is sufficient for stable storage. The lactic acid contents in Auxu were from 2.57 to 3.21%, which is higher than other cultivars. The harvesting stages did not affect to the concentrations of butyric acid and acetic acid in all cultivars. These results indicate that the harvesting stage is more important for the quality of kenaf silage than cultivar differences. And kenaf silage could be also used as fodder for ruminants.
        35.
        2014.06 서비스 종료(열람 제한)
        May-Thurner syndrome is caused by blockade of local venous flow due to local vascular intimal proliferation, caused by repeated pulsatile compression of the iliac or iliofemoral vein between the iliac artery and the lumbar spine. In this case, we confirmed May-Thurner syndrome using lower extremity computed tomographic angiography and venography. However, on venography, it was impossible to distinguish the left iliac vein from the collateral vein; a thrombus was also seen, although some of the thrombus was not seen clearly. These problems were overcome with use of intravascular ultrasound. We report on intravascular ultrasound guided treatment of May-Thurner syndrome.
        36.
        2014.06 서비스 종료(열람 제한)
        May-Thurner syndrome is associated with deep vein thrombosis resulting from chronic compression of the iliac vein against the lumbar vertebrae caused by the overlying common iliac artery. Stent insertion into the compressed lesion is used in treatment of May-Thurner syndrome. Various complications can occur during angioplasty while using a stent. Among these complications, shrinkage of the vein below the stent, a rare complication, was observed in our hospital during treatment of a patient with May-Thurner syndrome. Different complications can occur when venous angioplasty is performed, unlike that when arterial angioplasty is performed.
        37.
        2013.12 KCI 등재 서비스 종료(열람 제한)
        Transforming growth factor (TGF) family is well known to induce the chondrogenic differentiation of mesenchymal stem cells (MSC). However, the precise signal transduction pathways and underlying factors are not well known. Thus the present study aims to evaluate the possible role of C2 domain in the chondrogenic differentiation of human mesenchymal stem cells. To this end, 145 C2 domains in the adenovirus were individually transfected to hMSC, and morphological changes were examined. Among 145 C2 domains, C2 domain of protein kinase C eta (PKCη) was selected as a possible chondrogenic differentiation factor for hMSC. To confirm this possibility, we treated TGFβ3, a well known chondrogenic differentiation factor of hMSC, and examined the increased-expression of glycosaminoglycan (GAG), collagen type II (COL II) as well as PKCη using PT-PCR, immunocytochemistry and Western blot analysis. To further evaluation of C2 domain of PKCη, we examined morphological changes, expressions of GAG and COL II after transfection of PKCη -C2 domain in hMSC. Overexpression of PKCη-C2 domain induced morphological change and increased GAG and COL II expressions. The present results demonstrate that PKCη involves in the TGF-β3-induced chondrogenic differentiation of hMSC, and C2 domain of PKCη has important role in this process.
        38.
        2012.07 서비스 종료(열람 제한)
        Kenaf (Hibiscus cannabinus) is an annual herbaceous plant of the family Malvaceae that has been planted in Africa for more than 4000 years and used as source of fiber, energy and feed stock. Also, kenaf seeds are good source for edible oil used for first class cooking oil and margarine production. The seeds can be used for lubrication, soap, paint and varnishes. This study was carried out to evaluate fatty acids variation among sixteen kenaf germplasm and gamma-ray induced mutants derived from Jinju and Auxu. Linoleic, oleic, and palmitic acid were the predominant fatty acids in all kenaf seed oils. The sixteen accessions showed a wide range of fatty acid compositions, spanning from 28.94 to 43.36% saturated, 56.64 to 71.05% total unsaturated, 15.52 to 46.85% monounsaturated, and 13.56 to 48.97% polyunsaturated fatty acids. The mutant lines derived from Jinju, significantly surpassed parental mean for all the palmitic and oleic acid. Also, the mutant lines derived from Auxu showed broad ranges of variation in oleic and linoleic acid and narrow ranges of variation in stearic and palmitic acid. The relative amount of monounsaturated fatty acids (MUFA) were increased at all the gamma-ray induced mutants. These results will provide a valuable information to assist parental selection of kenaf breeding.
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