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        검색결과 968

        741.
        2017.03 KCI 등재 서비스 종료(열람 제한)
        The process of spontaneous abortion involves a complex mechanism with various cytokines, growth factors, and hormones during the pregnancy. However, the mechanism underlying spontaneous abortion by pro- and antiinflammatory cytokines in the serum during the pregnancy is not fully understood. Therefore, the purpose of this study was to examine the relationship between the serum levels of pro- and anti-inflammatory cytokines and spontaneous abortion using the CBA/j × DBA/2 mouse model. Serum levels of pro-inflammatory cytokines, such as IFN-γ, IL-1α and TNF-α were not increased in abortion model mice, but anti-inflammatory cytokines, such as IL-4, IL-13 and IL-1ra were decreased compared to normal pregnant mice. In addition, serum levels of chemokine, such as SDF-1, G-CSF, M-CSF, IL-16, KC and MCP-1 were decreased in abortion model mice compared to normal pregnant mice. However, the expression levels of nesfatin-1/NUCB2 mRNA and protein in the uteri of implantation sites were significantly higher in abortion model mice than normal pregnant mice. These results suggest that uterine nesfatin-1/NUCB2 expression may be down-regulated by inflammatory cytokines and chemokines in the serum of pregnant mice. Moreover, this study suggests the possibility that nesfatin-1/NUCB2 expressed in the implantation sites may be associated with the maintenance of pregnancy.
        742.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        We compared the germination rate of dehisced ginseng (Panax ginseng) seeds that were dried under two different conditions, slowly at 15℃ [relative humidity (RH) 10-12%] and rapidly under a laminar airflow cabinet at 25℃ (RH 22-25%). The measurements showed that drying rate and seed moisture content (SMC) play important roles in storage ability and vigor. The seeds that were dried rapidly at 25℃ showed high GR compared with the seeds that were dried at 15℃ after 6 and 12 months of storage at -80℃ irrespective of MC. Seeds dried slowly at 15℃ with MC higher than 7.0% showed high GR maintenance after storage at -18℃ and at 4℃ in comparison with rapidly dried seeds. However, the GR of the slowly desiccated seeds decreased as mean SMC was reduced to less than 5.0%, whereas the rapidly dried seeds were distinguished by significantly high GR irrespective of the storage conditions. The ginseng seeds desiccated under different conditions showed differences in storage performance. Seeds with 7-9% MC that were dried slowly at 15℃ for 5-7 days showed high GR after 4℃ and -18℃ storage; however, longer periods of desiccation decreased the germination level remarkably compared with that of rapidly dried seeds.
        743.
        2016.12 KCI 등재 서비스 종료(열람 제한)
        Sweet potato (Ipomoea batatas L.) shoot tips grown in vitro were successfully cryopreserved by encapsulationvitrification. Encapsulated explants are very easily manipulated, due to the relatively large size of the alginate beads, and a large number of samples can be treated simultaneously. In this study, the effects of sucrose preculture, cryoprotectant preculture, and post-warm recovery media on regrowth, following liquid nitrogen (LN) exposure, were investigated to establish an efficient encapsulation-vitrification protocol for sweet potato. Shoot tips of plants grown in vitro were precultured in 0.3 M sucrose for 2 d before encapsulation. Encapsulated shoot tips were pre-incubated in liquid MS (Murashige and Skoog) medium containing 0.5 M sucrose for 16 h, before preculturing in sucrose-enriched medium (0.7 M sucrose) for 8 h. Shoot tips were osmoprotected with 35% plant vitrification solution 3 (PVS3) for 3 h, before being dehydrated with PVS3 for 2 h at 25°C. The encapsulated and dehydrated shoot tips were transferred to 2 mL cryotubes, suspended in 0.5 mL PVS3, and plunged directly into liquid N. High levels of shoot formation were obtained for the cv. Yeulmi (65.7%) and Yeonwhangmi (80.3%). The regrowth rates of cryopreserved samples in Yeulmi (78.9%) and Yeonwhangmi (91.3%), following culture on ammonium-free MS medium for 5 d, were much higher than those cultured on standard MS medium (65.7% and 80.3%, respectively). This encapsulation-vitrification is a promising method for the long-term preservation of sweet potato.
        744.
        2016.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In December 2015, we have installed neutron monitors at the Jang Bogo station in Antarctica. The Jang Bogo station is the second science station which is located at the coast (74° 37.4´S, 164° 13.7´E) of Terra Nova Bay in Northern Victoria Land of Antarctica. A neutron monitor is an instrument to detect neutrons from secondary cosmic rays collided by the atmosphere. The installation of neutron monitor at Jang Bogo station is a part of transferred mission for neutron monitor at McMurdo station of USA. Among 18 tubes of 18-NM64 neutron monitor, we have completed relocation of 6 tubes and the rest will be transferred in December 2017. Currently, comparison of data from the neutron monitors of both two stations is under way and there is a good agreement between the data. The neutron monitors at Jang Bogo station will be quite useful to study the space weather when the installation is completed.
        745.
        2016.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The spatial size and variation of Arctic sea ice play an important role in Earth’s climate system. These are affected by conditions in the polar atmosphere and Arctic sea temperatures. The Arctic sea ice concentration is calculated from brightness temperature data derived from the Defense Meteorological Satellite program (DMSP) F13 Special Sensor Microwave/Imagers (SSMI) and the DMSP F17 Special Sensor Microwave Imager/Sounder (SSMIS) sensors. Many previous studies point to significant reductions in sea ice and their causes. We investigated the variability of Arctic sea ice using the daily sea ice concentration data from passive microwave observations to identify the sea ice melting regions near the Arctic polar ice cap. We discovered the abnormal melting of the Arctic sea ice near the North Pole during the summer and the winter. This phenomenon is hard to explain only surface air temperature or solar heating as suggested by recent studies. We propose a hypothesis explaining this phenomenon. The heat from the deep sea in Arctic Ocean ridges and/ or the hydrothermal vents might be contributing to the melting of Arctic sea ice. This hypothesis could be verified by the observation of warm water column structure below the melting or thinning arctic sea ice through the project such as Coriolis dataset for reanalysis (CORA).
        746.
        2016.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Interplanetary scintillation-driven (IPS-driven) ENLIL model was jointly developed by University of California, San Diego (UCSD) and National Aeronaucics and Space Administration/Goddard Space Flight Center (NASA/GSFC). The model has been in operation by Korean Space Weather Cetner (KSWC) since 2014. IPS-driven ENLIL model has a variety of ambient solar wind parameters and the results of the model depend on the combination of these parameters. We have conducted researches to determine the best combination of parameters to improve the performance of the IPS-driven ENLIL model. The model results with input of 1,440 combinations of parameters are compared with the Advanced Composition Explorer (ACE) observation data. In this way, the top 10 parameter sets showing best performance were determined. Finally, the characteristics of the parameter sets were analyzed and application of the results to IPS-driven ENLIL model was discussed.
        747.
        2016.10 서비스 종료(열람 제한)
        Background : Invitro antioxidant activity, polyphenol and flavonoid aglycone contents in black and green tea products of balloon flower leaves were investigated to provide valuable information for the further development and utilization of resources of Platycodon grandiflorum. Methods and Results : Flavonoid aglycone contents were investigated using HPLC (SHIMADZU, Japan) with a hypersil ODS column (125 mm × 4 mm, 5-μm particle, HP). DPPH and ABTS radical scavenging activities were measured by method of Lee & Lee (2004) with slight modification. Antioxidant activity, polyphenol and flavonoid contents in green tea were significantly higher than these in black tea. PC analysis indicated that first principal components explained 79.9% of the total variability for five traits investigated. PC2 explained 19.7% of the variation. Conclusion : It can be concluded from these results that these characteristics can reveal the active compound variation of black and green tea products of balloon flower leaves. These results provide scientific evidence for the utilization of balloon flower leaves.
        748.
        2016.10 서비스 종료(열람 제한)
        Background : Garlic is one of the important vegetables and a source of natural anti-oxidants. This study was carried out to investigate the antioxidant activities including 2,2-diphenyl-1-picr yl-hydrazil (DPPH), 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid (ABTS), ferric reducing antioxidant power (FRAP), reducing power (RP) and total polyphenol content (TPC) of A. ampel oprasum L. Methods and Results : DPPH, ABTS, FRAP, TPC, and RP were analyzed the extract of aerial plant part in 22 accessions of A. ampeloprasum by spectrophotometry mathod. A. tuberosum Rottler ex Spreng. was used as a control. DPPH was ranged from 0.35 to 3.06 ㎍ ASC ㎎-1 dw. ABTS and FRAP showed wide variation from 4.37 to 29.30 ㎍ Trolox ㎎-1 dw and 3.18 to 10.8 ㎍ ASC ㎎-1 dw, respectively. RP and TPC were ranged from 3.43 to 9.51 ㎍ GAE ㎎-1 dw, and 0.8 to 18.63 ㎍ ASC ㎎-1 dw, respectively. Cluster analysis of A. ampeloprasum germplasm was divided into two major groups. Group Ⅰ (7 accessions) characterized as higher antioxidant activities than the group Ⅱ (15 accessions) and had similar antioxidant activities with A. tuberosum as a control. FRAP value showed a significant strong positive correlation with DPPH (r = 0.868*) and ABTS activity (r = 0.826*). Principal component analysis showed that the first two principal components (PC1 and PC2) cumulatively explained 85.64 % of total variation. Conclusion : From the above results, we may suggest that A. ampeloprasum aerial parts might have useful as a new material for functional food.
        749.
        2016.10 서비스 종료(열람 제한)
        Background : Codonopsis lanceolata is a flowering perennial climber. The roots are used as medicinal materials or vegetables. C. lanceolata is distributed in India and East Asia such as China, Japan as well as Korea. Recently, demand for C. lanceolata is increasing as a healthy food. In South Korea, this plant is widely cultivated in Gangwon-do province. Although, C. lanceolata is one of the most important medicinal plants in Korea, an elite, inbred line or a variety has not been developed yet. Simple sequence repeat (SSR) marker is a powerful tool for analysis of genetic relationships. In addition, it is a useful tool for studying the non-reference plant genome, due to its even distribution throughout the genome, as well as its high polymorphism between individuals. Methods and Results : We constructed microsatellite-enrichment libraries using C. lanceolata genomic DNA, and obtained a total of 226 non-redundant contig sequences. Routine PCR was performed using gDNA as templates for the polymorphic markers screening. Finally, total 15 polymorphic SSR markers based on C. lanceolata genomic sequences were successfully developed. These markers were applied to 53 C. lanceolata collected from Korea. 103 alleles of the 15 SSR markers ranged from 3 to 19 alleles at each locus, with an average of 6.87. The average of observed heterozygosity and genetic diversity were 0.42 and 0.62, respectively. The average of polymorphism information content (PIC) value was 0.57. The genetic distance value ranged from 0.73 to 0.93, and there was no observed distinct group according to the collecting areas. Conclusion : We developed 15 novel SSR markers from C. lanceolata genomic sequences for further genetic studies. Also, we concluded that the lineage of C. lanceolata collected in Korea has not been established systematically.
        750.
        2016.10 서비스 종료(열람 제한)
        Background : In the herbal medicine market, Angelica gigas, Angelica sinensis, and Angelica acutiloba are all called "Danggui" and used confusingly. We aimed to assess the genetic diversity and relationships among 14 Angelica species collected from different global seed companies. Toward this aim we developed DNA markers to differentiate the Angelica species. Methods and Results : A total of 14 Angelica species, A. gigas, A. acutiloba, A. sinensis, A. pachycarpa, A. hendersonii, A. arguta, A. keiskei, A. atropurpurea, A. dahurica, A. genuflexa, A. tenuissima, A. archangelica, A. taiwaniana, and A. hispanica were collected. The genetic diversity of all 14 species was analyzed by using five chloroplast DNA-based simple sequence repeat (SSR) markers and employing the DNA fragment analysis method. Each primer amplified 3 - 12 bands, with an average of 6.6 bands. Based on the genetic diversity analysis, these species were classified into specific species groups. The cluster dendrogram showed that the similarity coefficients ranged from 0.77 to 1.00. Conclusions : These findings could be used for further research on cultivar development by using molecular breeding techniques and for conservation of the genetic diversity of Angelica species. The analysis of polymorphic SSRs could provide an important experimental tool for examining a range of issues in plant genetics.
        751.
        2016.10 서비스 종료(열람 제한)
        Background : Platycodon grandiflorum is a perennial plant and a member of Campanulaceae family. Since ancient times, they have been using P. grandiflorum as an important medicinal plant in Korea. Platycodin D is the most abundant saponin derived from P. grandiflorum and pharmacologically active component. Cytochrome P450s (CYPs) are important enzymes in the saponin biosynthesis. CYP is, in general, the terminal oxidase enzymes and essential roles in saponin biosynthesis pathway by hydroxylation or oxidaition of triterpene skeletons. Methods and Results : We tried to identify CYP genes related to saponin biosynthesis of P. grandiflorum through RNA-seq analysis. The sequencing was performed using Illumina Hi-Seq platform after cDNA library preparation. The produced reads were assembled using CLC Genomics Workbench software (CLC Bio, Inc.). We obtained 122,663 contigs and found 191 putative CYP genes. Familes of CYP716, CYP708, CYP93 and CYP51 were selected as putative saponin biosynthesis related gene families using phylogenetic relationship analysis. Conclusion : The results in this study could help to find the CYPs related to saponin biosynthesis pathway of P. grandiflorum.
        752.
        2016.10 서비스 종료(열람 제한)
        Background : Medicinal crop has been used in the traditional Asian medicinal methods. From ancient times, various kinds of medicinal crop are being cultivated in East Aisa including Korea, China and Japan. In Korea, they used a variety of medicinal plants in folk medicine and oriental medicine since ancient times. Molecular markers can be widely used in a variety of settings such as effective-loci estimation, genetic-diversity characterization, allelic-effect studies, gene-flow studies, quantitative-trait locus (QTL) mapping, and evolutionary studies. The genetic analyses of crops require large numbers of useful molecular markers for genetic or QTL identification, comparative mapping and breeding. Studying the genetic diversity and genetic relationship of crops can assist breeders. Crop genetics within a breeding program enable the economic and effective cultivar development. We tried to develop a variety of molecular markers from Angelica gigas genomic sequences for genetic studies and breeding. Methods and Results : A. gigas resources cultivated in Republic of Korea were collected. Fresh leaves were ground with liquid nitrogen and gDNA was extracted using a DNeasy Plant Mini kit (Qiagen, Valencia, CA, USA). We sequenced the whole genomes of five A. gigas accessions using Illumina HiSeq 2500 platform and identified genomic Simple Sequence Repeat (SSR) and InDel markers. DNA amplification was conducted using the PCR system (Bio-Rad T-100 Thermal Cycler). PCR products were separated by capillary electrophoresis on the ABI 3730 DNA analyzer (Applied Biosystems) and Fragment analyzer automated CE system (Advanced Analytical Technologies, Ankeny, IA, USA). Conclusion : We developed novel SSR and InDel markers from A. gigas genomic sequences for further genetic studies and breeding.
        753.
        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.
        754.
        2016.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        We report on a systematic analysis of the spin and superorbital modulations of the high-mass X-ray binary 4U 0114+650, which consists of the slowest spinning neutron star known. Utilizing dynamic power spectra, we found that the spin period varied dramatically during the RXTE ASM and Swift BAT observations. This variation consists of a long-term spin-up trend, and two ~1,000 day and one ~600 day random walk epochs previously, MJD 51,000, ~MJD 51,400-52,000, and ~MJD 55,100-56,100. We further found that the events appear together with depressions of superorbital modulation amplitude. This provides evidence of the existence of an accretion disk, although the physical mechanism of superorbital modulation remains unclear. Furthermore, the decrease of the superorbital modulation amplitude may be associated with the decrease of mass accretion rate from the disk, and may distribute the accretion torque of the neutron star randomly in time.
        755.
        2016.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        The correlation between meteorological data collected at the optical wide-field patrol network (OWL-Net) Station No. 1 and the seeing of satellite optical observation data was analyzed. Meteorological data and satellite optical observation data from June 2014 to November 2015 were analyzed. The analyzed meteorological data were the outdoor air temperature, relative humidity, wind speed, and cloud index data, and the analyzed satellite optical observation data were the seeing full-width at half-maximum (FWHM) data. The annual meteorological pattern for Mongolia was analyzed by collecting meteorological data over four seasons, with data collection beginning after the installation and initial set-up of the OWL-Net Station No. 1 in Mongolia. A comparison of the meteorological data and the seeing of the satellite optical observation data showed that the seeing degrades as the wind strength increases and as the cloud cover decreases. This finding is explained by the bias effect, which is caused by the fact that the number of images taken on the less cloudy days was relatively small. The seeing FWHM showed no clear correlation with either temperature or relative humidity.
        756.
        2016.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Inactive space objects are usually rotating and tumbling as a result of internal or external forces. KOREASAT 1 has been inactive since 2005, and its drift trajectory has been monitored with the optical wide-field patrol network (OWL-Net). However, a quantitative analysis of KOREASAT 1 in regard to the attitude evolution has never been performed. Here, two optical tracking systems were used to acquire raw measurements to analyze the rotation period of two inactive satellites. During the optical campaign in 2013, KOREASAT 1 was observed by a 0.6 m class optical telescope operated by the Korea Astronomy and Space Science Institute (KASI). The rotation period of KOREASAT 1 was analyzed with the light curves from the photometry results. The rotation periods of the low Earth orbit (LEO) satellite ASTRO-H after break-up were detected by OWL-Net on April 7, 2016. We analyzed the magnitude variation of each satellite by differential photometry and made comparisons with the star catalog. The illumination effect caused by the phase angle between the Sun and the target satellite was corrected with the system tool kit (STK) and two line element (TLE) technique. Finally, we determined the rotation period of two inactive satellites on LEO and geostationary Earth orbit (GEO) with light curves from the photometry. The main rotation periods were determined to be 5.2 sec for ASTRO-H and 74 sec for KOREASAT 1.
        757.
        2016.06 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In this work, based on our previous calculations of spectral energy distributions for a sample of Fermi blazars (Fan et al. 2015a), we calculated the radio loudness and performed correlation analyses. Our analysis results show that radio loudness is closely anti-correlated with synchrotron peak frequency and positively correlated with gamma-ray luminosity, suggesting that the gamma-ray emissions are strongly beamed.
        758.
        2016.05 서비스 종료(열람 제한)
        Background : Wild-cultivated P. ginseng (WCG) is a specific ginseng in Korea which depends on artificial forest growth method. To obtain a WCG which is similar to wild ginseng (WG), this method usually performed in a mountain using seeds or seedlings of cultivated ginseng (CG) and WG. Recently, very high price of WCG caused the problem that Panax notoginseng or Panax quinquefolium are sold as WCG in Korean market. This is concerned as a serious problem to consumers. In this study, we tried to develop a method to discriminate WCG, CG or WG using simple sequence repeat (SSR) markers and phylogenetic analysis. Methods and Results : WCG samples (3, 5, or 6-years old) were collected in Hoengseong, Gangwondo. DNA extraction was performed using CTAB method. SSR markers were collected from the published papers. After test PCR using the markers, one of the primer pair was labeled with fluorescence dye (FAM, NED, PET, or VIC) and Gene Scan analysis were performed. NTsys-PC program was used for the phylogenetic analysis of the data. Eight SSR markers were collected from the published literature and used for the analysis. From the 8 tested SSR markers, 7 SSR markers showed polymorphism between varieties. GenScan analysis were performed using the selected SSR markers to analyze the phylogenetic relationship of WCG. Conclusion : Phylogenetic analysis showed the relationship between WCG and P. ginseng cultivars and the seven SSR markers used in this study are able to distinguish Wild-cultivated P. ginseng.
        759.
        2016.05 서비스 종료(열람 제한)
        Background : Angelica gigas, also called Dang Gui or Korean Angelica, is a major medicinal herb used in Asian countries such as Korea, Japan and China. A. gigas has many active constituents such as dercursin, decursinol angelate, nodakenetin, nodakenin, β-sisterol or α -pinene. But, there is no research on the gexpression of the genes related to saponin biosynthesis from A. gigas. In this study, we compared the expression of saponin biosynthesis related genes from various organs of A. gigas. Methods and Results : The reads of Angelica gigas mRNAs were produced using Illumina Hiseq 2000, and the reads were assembled to produce 113,597 contigs using CLC Genomic Workbench. To select the saponin biosynthesis genes, assembled contigs were subjected to BLAST analysis at NCBI site. RNAs were extracted from five tissues, roots, stems, flowers, old leaves and young leaves of A. gigas. We produced total of 16 gene specific primers and used for RT-PCR. PCR conditions composed pre-denaturation at 95℃ for 3min, then 35 cycles of 95℃ for 30 sec, 57℃ for 30sec and 72℃ for 1min, and a final extension at 72℃ for 5min. Electrophoresis performed at 100 V, 30 min using 1.2% gel. Our experiment shows that A. gigas has several genes related to saponin biosynthesis and the genes were expressed from variety of organs. Conclusion : From the above results, we may suggest A. gigas genes related to the biosynthesis of saponins.
        760.
        2016.05 서비스 종료(열람 제한)
        Background : Codonopsis is a flowering plants belong to the family Campanulaceae, and has many kinds of medicinal properties. As currently recognized, two other groups, Campanumoea and Leptocodon, are included in the Codonopsis. The enlarged genus Codonopsis is distributed in Eastern, Southern, Central, and Southeastern Asia. C. lanceolata, C. clematidea and C. pilosula has many kinds of medicinal properties and this plants are used as medicinal and edible plants. C. ovata and C. mollis are distributed in Pakistan Kashmir and Himalaya mountains at an altitude of about 3,000 m, and flowers bloom in July to August. Methods and Results : In this study, we analyzed the genetic diversity of 5 Codonopsis species using 8 SSR markers base on C. lancelolata genomic sequences. Samples were obtained from fresh leaves of 5 plants from each species and genomic DNA was extracted using CTAB method. PCR was performed in total 20μl reaction volume containing 20 ng of DNA template and 5 pmole of primers. PCR conditions composed pre-denaturation at 95℃ for 5 min, then 35 cycles of 95°C for 30 sec, 60°C for 30 sec and 72°C for 30 sec, and a final extension at 72℃ for 30 min. The amplified band sizes ranged from 74 to 301 bp and clearly showed single or doble bands in eletrophoresis. From the phylogenetic analysis, C. lanceolata was grouped together, but the others were not grouped together according to the species. Conclusion : We concluded that C. lanceolata cultivated in Korea is different from the other species, and the eight SSR markers used in this study are able to distinguish C. lanceolata from the other species.