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        검색결과 79

        43.
        2017.12 KCI 등재 서비스 종료(열람 제한)
        본 연구는 원자력 발전소가 인접해 있는 부산지역 경찰관들의 원자력 사고와 방사능 테러에 대한 인식 과 대처 방안을 파악함으로써, 이와 관련한 정책 수립에 기초자료를 제공하고자 하였다. 부산광역시에 근 무하는 221명의 경찰을 대상으로 하였으며, 조직구성, 지휘능력, 여론운영 등으로 설문을 구성하여 재난대 응 인식도를 분석하였다. 그 결과, 성별 및 지휘계급에 따른 재난대응 인식은 큰 차이가 없는 것으로 나타 났다(p>.05). 연령의 경우 지휘능력에 대한 통계적 차이(p<.05)를 보였으며, 근무경력에 따른 지휘능력도 통 계적 차이(p<.05)를 나타냈다. 상관관계 분석 결과, 조직구성에 대한 인식과 지휘능력, 여론운영 3가지 항목 이 +0.5 이상으로 정적상관을 나타냈다(p<.01). 전반적으로 경찰 체제에 대해 긍정적인 것으로 나타났으며, 방사선사고 및 테러 발생 시 경찰의 업무를 잘 인식하고 있었다.
        44.
        2017.05 서비스 종료(열람 제한)
        Background : Rehmannia glutinosa is a perennial herb belonging to the family Scrophulariaceae. Its roots have been utilized as a traditional medicine but the aerial parts (flower, flower stalk, leaf) were not used. In this paper, we aimed to determine the content of three compounds [aucubin, catalpol, and γ-aminobutyric acid (GABA)] in different organs of R. glutinosa. Methods and Results : The flower, flower stalk, leaf, and root of R. glutinosa were harvested in the end of August. The aucubin and catalpol were analyzed by LC/MS, whereas GABA was analyzed by GC/MS. The aucubin content was the highest in the leaf, while catalpol and GABA were the highest in the flower. The aucubin content of in the leaf was 1.43, 0.81, and 1.07 ㎎/g, respectively. The catalpol content of flower in Dakang, Tokang, and Suwon 9 was 41.06, 28.78 and 37.48 ㎎/g, respectively. The GABA content of flower in Dakang, Tokang, and Suwon 9 were 0.79, 0.76 and 0.65 ㎎/g, respectively. Conclusions : The contents of aucubin, catalpol, and GABA were higher in leaf and flower than that of root. This study provides the important information of R. glutinosa leaf and flower as a potential supplement.
        45.
        2016.10 서비스 종료(열람 제한)
        Background : Ixeris genus has been used in traditional medicines as stomachics, sedatives, and diuretics. Ixeris dentata var albiflora is a kind of perennial herbaceous plant and one of the plants of the genus Ixeris (Asteraceae). It is well-known for edible wild vegetable in Korea, China, Japan, and Mongolia. Specially, Korean has its root and young leaf with appetizing vegetable due to bitter taste. Methods and Results : We isolated 8 genes that are involved in carotenoid biosynthesis using the Illumina/Solexa HiSeq2000 platform. In this study, a full-length cDNA clone encoding phytoene synthase (IdPSY), phytoene desaturase (IdPDS), ξ-carotene desaturase (IdZDS), lycopene β-cyclase (IdLCYB), and zeaxanthin epoxidase (IdZEP) and partial-length cDNA clones encoding lycopene ε-cyclase (IdLCYE), ε-ring carotene hydroxylase (IdCHXE), and β-ring carotene hydroxylase (IdCHXB2) were identified in I. dentata. The theoretical molecular weight (MW) and isoelectric point values of 8 genes were investigated. Sequence analyses revealed that these proteins shared high identity and conserved domains with their orthologous genes. IdPSY, IdPDS, IdZDS, IdLCYB, IdCHXB2, and IdZEP were constitutively expressed in the roots, stems, leaves, and flowers of I. dentata. Conclusion : Our study on the biosynthesis of carotenoids in I. dentata will provide basic data for elucidating the contribution of carotenoids to the considerable medicinal properties of I. dentata.
        46.
        2015.09 서비스 종료(열람 제한)
        Hepatocytes and hepatic progenitors derived from human ES cells may be a useful source for clinical application. Therefore, identification and purification of these cell types would be following important issues. There are very few candidate surface markers that can be used to identify and purify hepatic progenitor cells. In addition, indocyanine-green can be uptaken by mature hepatocytes, but cannot be applied for fluorescence activated cell sorting (FACS) due to its long emission wavelength. In the present study, we tested EpCAM as a potential marker for magnetic-activated cell sorting (MACS) of hepatic progenitors and also modified indocyanine-green into fluorescent indomonocarbocyanine for FACS-mediated sorting of mature hepatocytes after differentiation of human ES cells. Hepatic progenitor cells were sorted by MACS after incubation with anti-human EpCAM antibodies. After the final differentiation, the differentiated cells and mouse primary hepatocytes (control group) were incubated with indomonocarbocyanine and were sorted by FACS. MACS and immunocytochemistry data showed that approximately 45% of differentiated cells were EpCAM-positive cells. EpCAM-positive cells expressed α-fetoprotein, FOXa2, HnF4a, and CK18. Differentiation efficiency into albumin-positive cells was significantly higher in EpCAM-positive cells, compared to EpCAM-negative cells. Importantly, indomonocarbocyanine successfully stained cells that expressed ALB. Furthermore, FACS analysis data showed that the purity of hepatocytes that expressed albumin was significantly increased after purification of indomonocarbocyanine-positive cells. Our data demonstrated that human ES cell-derived hepatic progenitors can be efficiently isolated by MACS using EpCAM antibody. In addition, we also showed that indomonocarbocyanine can be successfully used to identify and purify mature hepatocytes using FACS.
        47.
        2015.09 서비스 종료(열람 제한)
        Highly homogeneous and functional stem cell-derived hepatocyte-like cells (HLCs) are considered a promising option in the treatment of liver disease and the development of effective in vitro toxicity screening tool. However, the purity of cells and expression and/or activity of drug metabolizing enzymes in stem cell-derived HLCs are usually too low to be useful for clinical or in vitro applications. Here, we describe a highly optimized differentiation protocol, which produces more than 90% albumin-positive HLCs with no purification process. In addition, we show that hepatic enzyme gene expressions and activities were significantly improved by generating three-dimensional (3D) spheroidal aggregate of HLCs. The 3D differentiation method increased expressions of nuclear receptors that regulate the proper expression of key hepatic enzymes. Furthermore, a significantly increased hepatic functions such as albumin and urea secretion were observed in 3D hepatic spheroids and HLCs in the spheroid exhibited morphological and ultrastructural features of normal hepatocytes. Importantly, we show that repeated exposures to xenobiotics facilitated the functional maturation of HLC, as confirmed by increased expression of genes for drug metabolizing enzymes and transcription factors. In conclusion, the 3D culture system with repeated exposures to xenobiotics may be a new strategy for enhancing hepatic maturation of stem cell-derived HLCs as a cell source for in vitro high-throughput hepatotoxicity models.
        48.
        2015.09 서비스 종료(열람 제한)
        Hepatocyte-like cells (HLCs) derived from human pluripotent stem cells have received extensive attention in the development of drug screening and toxicity testing. However, it has been reported that stem cell-derived HLCs showed hepatic functions that were too limited to be of use in drug screening and toxicity testing, possibly due to the lack of sufficient intercellular communication under conventional two-dimensional (2D) culture conditions. Therefore, a 3D differentiation system may overcome the in vitro limitation of 2D culture to produce stem cell-derived hepatocytes with mature metabolic functions. In this study, the feasibility of using a silicone-based spherofilm, specifically designed to produce spherical cell clusters, to generate uniformly sized 3D hepatic spheroids from hESCs was investigated. Hepatic spheroids generated on the spherofilm showed more homogenous size and shape than those generated in conventional low-attachment suspension culture dishes. Results of immunohistochemical analysis showed that expression of the mature hepatic marker albumin (ALB) increased over time during the hepatic maturation process. Furthermore, the 3D culture system mimicked the in vivo 3D microenvironment. Laminin, which is an important component of hepatic ECM, was expressed in hepatic spheroids. The results of immunohistochemical analysis indicated that the 3D culture environment is capable of generating an in vivo-like microenvironment. In addition, quantitative PCR analysis showed that the mature hepatic marker ALB and cytochrome P450 (CYP) enzymes CYP3A4 and CYP3A7 were expressed at higher levels in 3D culture than in 2D culture. This indicates that the 3D culture system is suitable for hepatic maturation and that our size-controlled 3D culture conditions might accelerate hepatic function. These results suggest that 3D hepatic spheroids significantly enhance metabolic maturation of hepatocytes derived from hESCs
        49.
        2015.07 서비스 종료(열람 제한)
        Seed color is an important factor affecting physiological and developmental process in wheat. One of the plant pigments, anthocyanins are a group of flavonoid compounds well known as pigments responsible for blue, purple, red, or yellow coloration of plant tissues. In this study, we investigated the pigmentation of purple and yellow color seed according to wheat grain developmental stages. The contents of anthocyanin and chlorophyll in the purple and yellow seeds were measured. Chlorophyll contents were changed similarly in both purple and yellow color seed, and no significant difference was observed between them. In purple color seed, the content of anthocyanin was significantly induced compared with yellow color seed. The individual anthocyanin components were investigated by ultra performance liquid chromatography (UPLC). Cyanidine-3-glucoside (C3G) and peonidine-3-glucoside (P3G) were detected as predominant anthocyanin in purple color wheat. To investigate whether structural genes in anthocyanin biosynthesis were involved in the trait differences between purple and yellow color seed, we examined the expression of anthocyanin biosynthesis-related genes (CHS, CHI, F3H, DFR, ANS, UFGT) and MYB transcription factor in developing wheat grains by using qRT-PCR. This study indicates that the expression of anthocyanin biosynthesis-related genes and MYB transcription factors correlate with anthocyanin levels of grain.
        50.
        2015.07 서비스 종료(열람 제한)
        To define whole genome-level of structural variation by ionization energies and radiation doses in plant, the seeds of Ilpum rice cultivar were acutely irradiated with gamma rays (100Gy, 200Gy, and 400Gy) and ion-beams (20Gy, 40Gy, and 80Gy), respectively. Six M1 rice plants were re-sequenced by Hi-Seq2500 with Ilpum cultivar as control. The average sequencing coverage of the individuals was 10.6X, and the average mapping rate to the rice reference genome (IRGSP-1.0) sequence was 96.95%. The individual plants were irradiated with gamma-400Gy and ion-50Gy had highest variation of SNP with 471,837 and 469,147, respectively. The number of insertion/deletion was 77,500 and 77,106, the synonymous and frame-shift were 7,859 and 7,763 in above two individuals. Although high genome variation shown between Ilpum cultivar and irradiated individuals, there were non-correlation between number of variation and radiation doses. However, five individuals, except ion-20Gy, showed 33 common variant blocks (CVBs) spanning 6 Mb in whole rice genome (1.6%). The CVBs were distributed on 12 rice chromosomes, Chromosome 6 had biggest CVB (5 blocks, 1.3Mb), whereas chromosome 9 had smallest CVB (0.01Mb). Total five hundred fifty one genes were in CVBs which can regard radiation sensitive genes or may be regarded as radiation hot spots in rice genome. This study will contribute to the improvement of the radiation mutation breeding research in genetic and genomic aspect.
        51.
        2014.07 서비스 종료(열람 제한)
        Gamma irradiation has been used as a tool for plant mutation breeding to select new cultivar with improved characteristics. Generally, the irradiation of seeds with high doses of gamma rays disturbs the synthesis of protein, hormone balance, and enzyme activity. And also, high dose of gamma rays to reduce plant height, number of tiller, and root length, although the effect of gamma-irradiated plants may depend on the species and cultivar or stress conditions. Biological effects of radiations can be divided into two types according to dose range and periods of exposure. Acute irradiation represents exposure to high-dose of irradiation over short period time, whereas the chronic irradiation is comprised of exposure to low doses of radiation over extended period of time. To compare the effects of acute and chronic exposure to ionizing radiation on two wheat cultivars (K4191 and Geumgangmil), we measured their germination rate, seedling height, and root length. In order to understand the influence of antioxidant-related genes and DNA repair-related genes, we used qRT-PCR methods to identify their expression levels. To study the behavior of a radiation-induced free radical, gamma-irradiated seeds were used for ESR spectroscopy. Plant growth pattern was showed positive correlation with ESR results. This study indicates that low level chronic radiation exposure is even more serious effects than short doses of high level radiation according to different wheat cultivar.
        52.
        2014.07 서비스 종료(열람 제한)
        Chronic gamma irradiation can be used an alternative mutation breeding methods for induction of many useful mutants. Seedlings of purple-colored wheat plants were irradiated with wide range doses of chronic gamma-rays (20, 25, 30, 40, 50, 70, 100, 125, 150, 200, 250, 300 Gy) during 6 weeks at gamma-phytotron in the Korea Atomic Energy Research Institute, respectively. To identify the biological responses purple-colored wheat, we examined the plant height, chlorophyll, carotenoid and total anthocyanin contents in leaf. Plant growth, chlorophyll and carotenoid contents in leaf were decreased when the dose rate increased. Anthocyanin contents were increased with the increase of the radiation dose until 50 Gy treatment. To confirm the real contents of anthocyanin, we also investigated cyanidin-3-glucoside in purple-colored wheat leaf by using UPLC analysis. These results indicate that anthocyanin accumuation was observed under chronic gamma irradiation.
        53.
        2014.07 서비스 종료(열람 제한)
        Perilla frutescens (L.) is an edible plant, not only used as s food ingredient, but also in skin cream, soaps, and medicinal preparetions. ‘Atom-Ros’, a perilla (Perilla frutescenc (L.) Britt. cv. Chookyoupjaso was developed in 1995 by 200 Gy gamma irradiation-mutagenesis. This new cultivar has high rosmarinic acid content more than two fold compare with ‘Chookyoupjaso’ control. The observed phenotypical difference was changed leaf color of the ‘Atom-Ketone’ from violet to green. The yield potential of this cultivar (123.5 kg/10a) was 2.14 fold higher than that of ‘Chookyoupjaso’ (57.65 kg/10a). The methanol extracts of ‘Atom-Ros’ were tested for inhibition of nitric oxide (NO) production in lipopolysaccharide (LPS)-stimulated RAW 264.7 macrophase cells. Atom-Ros showed significant inhibition of NO production. This rosmarinic acid extracted from ‘Atom-Ros’ has a good potential to be developed as an antioxidant agent.
        54.
        2014.07 서비스 종료(열람 제한)
        Perilla frutescens (L.) is an annual herbaceous and ornamental plant in the Lamiaceae family. Perilla frutescens (L.) Britt.cv.Chookyoupjaso were irradiated using a 200 Gy gamma ray in 1995. By HPLC analysis, this new cultivar significantly induced isoegomaketone content compared with ‘Chookyoupjaso’ control. The phenotypical difference was the changed leaf color of the ‘Atom-Ketone’ from violet to green. The yield potential of this cultivar (106 kg/10a) was 1.83 folds higher than that of ‘Chookyoupjaso’ (57.65 kg/10a). The methanol extracts of ‘Atom-Ketone’ inhibit nitric oxide (NO) production in LPS-stimulated RAW 264.7 cells. This extract was further partitioned using ethyl acetate (EtOAc), butanol (BuOH), and water. The EtOAc fraction (EF-Atom-Ketone) was evaluated for antiinflammatory activities. These results indicated that the EF-Atom-Ketone reduced NO production by inhibiting inducible nitric oxide synthase (iNOS) expression. The EF-Atom-Ketone treatment also significantly diminished expression of MCP-1 and IL-6. Therefore, ‘Atom-Ketone’ reveals the potential therapeutic use of bioactive
        55.
        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.
        57.
        2013.08 서비스 종료(열람 제한)
        MFG-E8 (Milk fat globule-epidermal growth factor VIII), also called lactadherin or BA46, SED1 is a glycoprotein found in milk and mammary epithelial cells, it is a major protein component associated with milk fat globule membrane. Previously, our study showed that expression of MFG-E8 is gradually increased with hepatic differentiation of human embryonic stem cells (hESCs). Therefore, we hypothesized that MFG-E8 would be an early cancer stem cell marker, which may predict cancer progression. Our results showed that MFG-E8 was expressed in various human cancer cell lines such as HepG2, Hep3B, and Huh7. Production and secretion of the MFG-E8 were also confirmed in the conditioned media of those three cell lines using enzyme-linked immunosorbent assay. Next, we analyzed the MFG-E8 expression in 11 clinical cases of cholangiocellular carcinoma (CC) and 33 cases of hepatocellular carcinoma (HCC) by immunohistochemistry and examined the potential correlation with β-catenin and AFP, which are known cancer markers. According to hitological criteria, the progression of HCC and CC was evaluated and classified into high, low, metastatic, and well-, moderate-, poor-differentiated, respectively. Statistical analysis indicated that incidence of both HCC and CC is significantly associated with male compared to female (P<0.05). Tumor size also has positive correlation with age (r2=08948). Our immunohistochemistry data showed that MFG-E8 was expressed both HCC and CC tissue. Interestingly, the MFG-E8 expression was significantly increased with cancer progression (P<0.05) in both cases. Additionally, b-cateninexpression was increased and its localization was changed from membrane to cytoplasm and nucleus with the degree of HCC. Likely b-catenin, AFP was also increased with the degree of HCC but it was not correlated with severalty of CC. Importantly, both AFP and b-catenin were highly co-localized with MFG-E8 in HCC. These results suggest that MFG-E8 may have important physiological roles and its expression in HCC and CC would be considered as an important prognostic factor.
        58.
        2013.07 서비스 종료(열람 제한)
        Copy number variations (CNVs) are considered major sources of genetic variation, and CNVs may influence phenotypic variation and gene expression. To detect CNVs, rice seeds were exposed with 100~400 Gy of gamma-ray (GA, 60Co), cosmic-ray (CR) by Russia ISS, and 30 and 40 Gy of ion beam (IB, 220 Mev carbon ion). After the exposed rice seeds were cultured in 1/2 MS medium for 14 days, they were used for array-based Comparative genomic hybridization (CGH) analysis using Agilent’s RICE CGH array. As a results, the highest number of CNVs (Gain 808 and Loss 24,080) were detected in the CR treatment, whereas GA100 (100 Gy of GA) was identified the least CNVs. Compared individual chromosome, the chromosome 8 and 11 were identified the highest CNVs, the chromosome 3 had the least CNVs. Most of identified CNVs existed in the range of 10~500kb. In particular, the same CNV locations among different types of ionizing radiation were observed in chromosome 12, and these CNVs contained the commonly 5 amplified genes, containing retrotransposon protein, NADH-ubiquinone oxidoreductase chain 3, heavy metal transport/detoxification protein domain containing protein, and 2 unknown proteins. Other studies were reported that Ty1 (Long Terminal Repeat-retrotransposon family 1) transcription and retrotransposition were induced by different environmental stresses such as ionizing radiation, UV-light exposure, DNA damage and nutrient starvation in Saccharomyces cerevisiae. Our results also show that retrotransposon protein (LOC_Os12g34016) was specifically amplified by different types of ionizing radiation.
        59.
        2013.07 서비스 종료(열람 제한)
        VitE (tocotrienols and tocopherols) are micronutrients with antioxidant properties synthesized by photosynthetic bacteria and plants that play important roles in animal and human nutrition. A new mutant line, T1001-1, was isolated from in vitro mutagenized population by ionizing radiation and shown to have increased VitE contents. The total VitE content was 26% increased in the T1001-1 mutant seeds compare with cv. Dongan (wild-type). In addition, we showed that the mutant confers retarded seedling growth during the early seedling growth stage in rice. To study the molecular mechanism of VitE biosynthesis, we used the rice microarray to identify genes that are upor down-regulated in T1001-1 mutant. In addition, we identified differentially regulated pathway using MapMan analysis, which provides deep insight into changes in transcript and metabolites. Our results enhanced the transcription of genes involved in starch and lipid metabolism in T1001-1 mutant. To identify the molecular mechanisms of the events involving transcription factors in tocopherol accumulation, we compared the expression patterns of transcription factors. The AP2-EREBP, WRKY, C2H2 transcription factor were up-regulated, whereas the MYB family was down-regulated in T1001-1 mutant. Our results demonstrate change of important transcript in high level of VitE accumulating rice mutant.
        60.
        2013.07 서비스 종료(열람 제한)
        To determine the expression levels of genes related to the salt stress response in rice, gene expression profiles were investigated through microarray analysis using the rice mutant line Till-II-877. There were no significant changes in physiological response under salt stress of the mutant increased less than that in the WT. The intensity of gene expression was analyzed and compared between the wild type and mutant lines using a microarray. Among the most significantly affected pathways, α-linolenic acid metabolism and linoleic acid metabolism (in lipid metabolism), fructose and mannose metabolism and glycolysis-gluconeogenesis (in carbohydrate metabolism), cysteine and methionine metabolism (in amino acid metabolism), and carbon fixation (in the energy metabolism of photosynthetic organisms) showed changes in gene expression levels under salt stress. These results further our understanding of the effects of salt stress in rice and may aid in the development of salt-tolerant rice cultivars.
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