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        검색결과 248

        201.
        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
        204.
        2013.08 서비스 종료(열람 제한)
        Hepatocytes derived from human embryonic stem cells (hESCs) may be a useful source for the treatment of diseased or injured liver. However, a low survival rate of grafted hepatocytes and immune rejection are still major obstacles to be overcome. We previously showed that secreted proteins (secretome) from hESC-derived hepatocytes had a potential therapeutic power in the tissue repair of injured liver without cell transplantation. The purpose of the present study was to discover key protein(s) in the secretome of hESC-derived hepatocytes using proteomic analysis and to study the tissue repair mechanism which may be operated by the secretomes. Purified indocyanine green+ hepatocytes derived from hESCs displayed multiple hepatic features, including expression of hepatic genes, production of albumin, and glycogen accumulation. The nano-LC/ESI-QTOF-MS analysis identified 365 proteins in the secretome of hESC-derived hepatocytes and the protein functional network analysis was conducted using the MetaCore TM from GeneGO. In addition, 20 tissue regeneration-related transcription factors (TFs) were extrapolated through further proteomic analysis. After intraperitoneal injection, the secretome significantly promoted the liver regeneration in a mouse model of acute liver injury. Protein functional network analysis on the secretome-induced regenerating liver confirmed 20 transcription factors (TFs) which were identified in the ICGhigh cells. The upreguation of these tissue repair-related TFs were validated by qPCR and western blotting on the regenerating liver tissues. These results demonstrate that application of the secretome analysis in combination with the protein functional network mapping would provide a reliable tool to discover new tissue-regenerating proteins as well as to expand our knowledge of the mechanisms of tissue regeneration.
        205.
        2013.07 서비스 종료(열람 제한)
        Genetically modified (GM) plant claims to be the solution to global poverty, and potentially solving environmental change and food requirement by increased human population. In this study, we were evaluating agronomic characteristics and chemical properties of two GM drought-tolerant rice (CaMsrB2-8 and CaMsrB2-23) compared with donor cultivars (Ilmi). Statistical analysis agronomic characteristics GM and donor rice showed no significant difference between both of them. Yield and appearance of rice grain, GM rice was a similar to the donor rice. Chemical composition analysis showed that GM drought-tolerant rice has no different with donor rice. This result indicated that GM drought tolerant rice has no big significant difference agronomic character and chemical properties; it can be solve food shortages in spite of drought condition.
        206.
        2013.07 서비스 종료(열람 제한)
        Quantitative trait locus (QTL) mapping is a highly effective approach for studying genetically complex forms of plant shattering. With QTLs mapping, the shattering loci can be described. SSR marker is based on the imformation of Simple Sequence Repeat and easy to analyze using PCR and has high reproducibility. For analyzing QTLs associated with shattering, we selected 219 SSR markers from 254 SSR markers and used them for implementing Mapmaker(Ver. 3.0) and Mapchart(Ver. 2.2). Mapmaker help to calculate distances between each markers and Mapchart is a program for drawing Genetic map. This Genetic map of rice (Oryza sativa L.) covering 2082.4 cM with 9.5 cM between makers in the Kosambi function has been constructed using 120 F1 DH plants from a single cross between the indica variety Chungchung and the japonica variety Nagdong.
        207.
        2012.09 KCI 등재 서비스 종료(열람 제한)
        Citrus is one of the major fruits produced in Korea. There are about 20 species mainly grown in Jeju Island, Korea. Four representative species, which are quite different in the shape of leaf and the taste of fruit, were selected and were used to profile the transcriptomes. These species are ‘Miyagawa Wase’ (C. unshiu Marcov.) satsuma mandarin, ‘Kiyomi’ (C. unshiu Marcov. × C. sinensis) mandarin hybrid, ‘Dangyuja’ (C. grandis) and ‘Natsudaidai’ (C. natsudaidai). Classification of the up-regulated and down-regulated genes using the Cluster of Orthologous Groups of proteins (COG) database reveals that the number of genes included in each group differed significantly among the four species. Several genes that showed significant differences in expression on the microarray were selected and their expression patterns were examined by reverse transcription- ploymerase chain reaction. Metabolic genes such as tyrosine decarboxylase and β-glucosidase ligase were found to be highly expressed in Miyagawa Wase, relative to other species. On the other hand, the expression level of mannose phosphate isomerase was lower in Miyagawa Wase. An efflux pump gene was found to be up-regulated in Kiyomi, whereas cinnamyl-alcohol dehydrogenase was down-regulated. β-carotene 15,15’-dioxygenase, which is involved in the vitamin metabolism, was up-regulated in Natsudaidai. Interspecific differentiations of gene expression are analyzed in terms of the metabolic pathways and their possible roles in citrus species.
        208.
        2011.10 KCI 등재 서비스 종료(열람 제한)
        A chemical, MNU-induced hulless barley mutant line designated as 'Mutant 98 (M98)' was developed from a Korean hulless waxy barley cultivar, 'Chalssalbori'. The objective of the study was to determine the genetic basis of 'M98' and the possibility of using 'M98' as breeding parent to improve lysine level. Compared to 'Chalssalbori', 'M98' had large embryo and higher lysine content in both the embryo and endosperm. Significantly different lysine content in 'M98' and the other high-lysine barley mutant stocks was observed for two years. However, the genotype by year interaction was not significant. 'M98' was higher than the other high-lysine barley mutant stocks in the percentage of lysine of total amino acid composition (0.75%). The trait of shrunken endosperm of 'M98', which was typical in the high-lysine mutants, was inherited by a single recessive gene. Based on seed morphology and lysine content of F1 seeds, 'M98' had a genetically different gene from the other high-lysine mutants for shrunken endosperm. Segregation of F2 for plump/shrunken endosperm did not fit the expected ratio of Mendelian inheritance except for only one cross combination (GSHO1784 (lys1)/M98). The amino acid analysis of F5 and F6 progenies from the cross between 'M98' and 'Chalssalbori' revealed that the attempt to increase the range of lysine content of plump lines did not go beyond the limit of the average high-lysine barley germplasm.
        210.
        2011.09 서비스 종료(열람 제한)
        Mesenchymal stem cells (MSC) are of great interest for cell-based therapies and tissue engineering approaches, as these cells are capable for extensive self-renewal and display a multilineage differentiation potential. Clinical application of these cells for degenerative and age-related diseases has been accumulating. However, preparation of MSC before the onset of the diseases, it needs to develop the cryopreservation method. Most cryopreservation methods include fetal bovine serum (FBS) which is essential for effective cryopreservation. Yet it should not be used clinically because of the potential risk of infection. In the present study, we investigated whether human serum albumin (HSA), human serum (HS), and knockout serum replacement (KSR) can be used as an alternative of FBS for cryopreservation of human adipose derived stem cells (hADSC). Cells cryopreserved with 9% HSA showed much higher viability after thawing compared with cells frozen with 5% or 1% HSA. Cells cryopreserved with 90% HS or KSR exhibited greater viability than cells frozen with 25% and 5% HS or KSR, respectively. Viability of cells frozen with 9% HSA, 90% HS or 90% KSR was comparable to that with 90% FBS. Morphology and proliferation ability of these cells were not affected by cryopreservation when compared the freshly obtained cells. Cryopreserved hADSC expressed transcription factor genes including Oct3/4, Nanog, Nestin and Sox2, which are related to the self-renewal of stem cells. Flow cytometric analyses showed that both fresh and cryopreserved hADSC were positive for the antigens of HLA-ABC, CD44, CD73, CD90, and CD105, CD166, and negative for HLA-DR, CD31, and CD34. Similar to fresh cells, cryopreserved hADSC could differentiate into mesodermal lineages, adipogenic, osteogenic, or chondrogenic cells. These results suggest that 9% HSA, 90% HS or 90% KSR can be used to replace FBS during successful cryopreservation of hADSC.
        211.
        2011.09 서비스 종료(열람 제한)
        The human eyelid adipose-derived stem cells (HEACs) are known as a candidate source for stem cell-based therapy. HEACs possess the ability to proliferate in vitro and multipotency to differentiate into adipogenic, osteogenic and chondrogenic cells. To be used later than the time of collection, a long-term storage is needed. In this study, we investigated stem cell characteristics after cryopreservation of HEACs for 6 months and 1 year in liquid nitrogen. Frozen-thawed stem cells have shown that cumulative cell and doubling numbers were similar to those of fresh HEACs. After thawing, HEACs expressed stem cell-related genes of SCF, NANOG, OCT4, and TERT, ectoderm-related genes of NCAM and FGF5, mesoderm/endoderm-related genes of CK18 and VIM. They also consistently expressed transcripts of the immune-related genes of HLA-ABC and β2M. To induce mesodermal differentiation, cell were cultivated in adipogenic, osteogenic or chondrogenic medium for 2~3 weeks. After each differentiation culture, HEACs expressed adipocyte-, osteocyte- and chondrocytespecific genes. They were also stained with Oil red O, von Kossa, or alcian blue, revealing adipogenic, osteogenic, or chondrogenic character, respectively. The results suggest that long-term storage up to 1 year do not affect their biological properties, HEACs may be suitable for clinical application on cell-based therapies.
        212.
        2010.04 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to examine the variations of seed hull color characteristics, the oil contents and fatty acid composition in 275 sunflower germplasms. The seed hull of sunflower germplasms were classified into 4 colors of white, black, grey, and brown. The grey color of seed hull was the highest percentage of 33.8%, whereas the white color of seed hull was the lowest percentage of 5%. Average oil content was 22.5% with a range from 11.7% to 45.5%. Average saturated fatty acid contents were 6.9%, while average content of unsaturated fatty acid was 93%. The average contents of fatty acids such as palmitic acid, stearic acid, oleic acid, and linoleic acid were 4.7%, 2.2%, 55.2%, and 38%, respectively. Comparing the oil contents and fatty acids among different seed hull colors, the highest content of oil was with grey seed hull color and the lowest with white seed hull color. Saturated fatty acid were higher in brown seed hull color. Unsaturated fatty acids were higher in grey and black seed hull colors. It could be observed that there was significant negative correlation(r=-0.998**) between linoleic and oleic acid content, and also L-value(Lightness of seed hull color) showed significant negative correlations with oil content, oleic acid content and linoleic acid content.
        216.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new cultivar of Dianthus caryophyllus "Deneb" was selected from the progenies of a cross "Mantovani" and "Deborah" in 1996 at the National Horticultural Research Institute, Rural Development Administration. It was finally selected in 2001 after the investigation of the characteristics for five years (1996-2001). "Deneb" was developed for a cut flower with a spray type. It has white with red edge flower color. The flower color is particularly clean and beautiful in indoor. It has a long flower stem and a long vase life. It is grown over 8℃ at night and under 25℃ at day. The cultivar was applied for a variety protection 2001 and was released to the growers and commercialized in 2002.
        217.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new cultivar of Dianthus caryophyllus "Phoenix" was selected from the progenies of a cross "Rossini" and "Charlotte" in 1997 at the National Horticultural Research Institute, Rural Development Administration. It was finally selected in 2001 after the investigation of the characteristics for four years (1997-2001). "Phoenix" was developed for a cut flower with a spray type. It has red flower color and lots of petals. It was moderately resistant against Fusarium oxysporum. Its flower looks like a rose when the outer petals bloom. It is grown over 8℃ at night and under 25℃ at day. The cultivar was applied for a variety protection 2001 and was released to the growers and commercialized in 2002.
        218.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new poinsettia cultivar 'Scarlet' was bred by the National Horticultural Research Institute (NHRI) in 2006. A cross was made between 'Christmas Eve', a variety with dark green leaves and dark red bracts, and 'Red Velvet', a red colored variety in 2003. 'Scarlet' was finally selected in 2006 after investigating the growth and flower characteristics from 2004 to 2006. 'Scarlet' has bright red colored and elliptic bracts and has absent or very weak intensity of rugosity between veins in bract. In comparison with the check variety, 'Red Velvet', plant height is tall, leafblade is long and narrow. Petiole is also longer than that of 'Red Velvet'. Short day response is fast and its bracts are fully colored 7 weeks after short day commencement.
        219.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new poinsettia cultivar 'Miss Maple' was bred by the National Horticultural Research Institute (NHRI) in 2006. A cross was made between 'Sonora Red', a variety with short plant height, dark green leaves and dark red bracts, and 'Cranberry Punch', a deep pink colored variety in 2003. 'Miss Maple' was finally selected in 2006 after investigating the growth and flower characteristics from 2004 to 2006. 'Miss Maple' has light red colored and obovate bracts, and has weak intensity of rugosity between veins in bract. Fully colored transitional leaves are so deeply lobed that they resemble the leaves of maple. Plant height is shorter than that of 'Cranberry Punch', the check variety. Short day response fast and its bracts are fully colored 7 weeks after short day commencement.
        220.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        A new spray chrysanthemum cultivar, 'Yellow PangPang' was released by National Horticultural Research Institute (NHRI), Rural Development Administration (RDA), in 2005. The cross between 'Restone' and 'Focus' was made in 2001. After evaluation for the characteristics including shading culture in summer and retarding culture in spring and consecutive selection from 2002 to 2005, final selection was made. The natural flowering time of "Yellow PangPang" is late October, but year-round flowering is possible by shading and illumination. It has pompon type flowers with yellow petals and greenish yellow flower center. It shows very strong stem hardness, especially flower neck, and excellent flower setting. The diameter of flower is 3.9 cm. The number of flowers per stem is 11.3 and the days to flower under the short day treatment is about 54 in autumn season. It has long vase life of 21 days in autumn.
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