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        검색결과 619

        441.
        2016.10 KCI 등재 서비스 종료(열람 제한)
        본 연구에서는 공극 기법의 고관전압 촬영에서 격자를 사용한 것과 같은 화질을 유지하면서 선량을 줄이는 방안을 제안하고자 하였다. 실험은 초점과 수용체와의 거리 180 cm에서 공극을 10 cm, 15 cm, 20 cm, 25 cm, 30 cm으로 하였으며 각각의 공극 거리에서 관전류를 15 mAs로 고정하고 관전압은 80 KvP, 85 kVp, 90 kVp, 95 kVp, 100 kVp로 하여 촬영을 하였다. 전통적인 방법인 격자를 사용하였을 때 촬영은 초점과 수용체와의 거리 180 cm에서 15 mAs, 107 kVp로 하였다. 실험결과 격자를 사용하여 촬영하였을 때 표면선량은 0.130 R로 나타났고 공극을 20 cm로 하였을 때의 표면선량은 0.124 R로 나타났으며 두 영상 간의 PSNR은 10.65 [dB]로 나타났다. 결론적으로 표면선량이 적으면서 산란선을 제거하여 격자를 사용하였을 때와 유사한 화질을 유지할 수 있는 공극의 거리는 20 cm로 나타났다. 연구의 결과는 공극을 이용한 방사선촬영에서 표면선량을 제거할 수 있는 지표로 사용할 수 있을 것으로 사료된다. 결론적으로 표면선량이 적으면서 산란선을 제거하여 격자를 사용하였을 때와 유사한 화질을 유지할 수 있는 공극의 거리는 20 cm로 나타났다. 연구의 결과는 공극을 이용한 방사선촬영에서 표면선량을 절감할 수 있는 지표로 사용할 수 있을 것으로 사료된다.
        442.
        2016.10 서비스 종료(열람 제한)
        Background : Cynanchum wilfordii and Cynanchum auriculatum belong to the Asclepiadaceae family and appear morphologically similar. In order to discriminate them, it is needed to find the presence of sap and the leaf shapes: C. auriculatum has a blade ovate leaf comparing to C. wilfordii. However, in the herbal medicine market, they have been handled as cut and dried roots. Due to their similar morphology, it is limited to distinguish the roots of C. wilfordii and C. auriculatum. Recently in Korea, it has been a critical issue to misuse these two roots in the herbal market and food industry. Thus, it is required to establish a robust tool for the discrimination and quality control of them. Methods and Results : To separation and characterization of flavor compounds, C. wilfordii and C. auriculatum samples were analyzed by head space solid phase micro extraction (HSS) fiber coupled with gas chromatography-mass spectrometry using Rtx-5MS (30 m x 0.25 mm x 0.25 μm) column. As a result, We have identified compounds of a few hundred in aliphatic aldehydes and aliphatic alcohols, alkenes and acids, aromatic compounds, aromatic compounds containing nitrogen & sulfur, etc,. In particular, The aliphatic and aromatic compounds had been clearly separated on the second dimensional direction by using two-dimensional GC. Conclusion : The volatile flavor compounds of C. wilfordii and C. auriculatum could easily analyzed without pre-treatment with improved resolution and sensitivity using HSS-GCxGC-TOFMS. We have identified compounds of a few hundred in C. wilfordii and C. auriculatum sample. And It was more accurately qualitative confirmed with separation of GCxGC and TSD. We have confirmed the PCA and PLS-DA Plot that was classified depending on C. wilfordii and C. auriculatum through multivariate statistical analysis of the identified flavor compounds.
        443.
        2016.10 서비스 종료(열람 제한)
        Background : Tetraploid plants are bigger in the size of fruits, leaves, stems, and roots than diploid plants due to bigger cells attributed to chromosome multiplication. The advantage of tetraploid plants includes breakdown of self-incompatibility and increase of disease resistance. This study was carried out to gain tetraploid resources for breeding of new boxthorn varieties having pest resistance, higher yield, and self-compatibility. Methods and Results : Tetraploid lines for this study were C0148-10 and C0412-1 from Cheongyang-jaerae (CJ), M0148-94 and M0148-120 from Myongan (MA), B0148-43 and B0148-78 from Bulro (BL), D0148-62 and D0148-72 from Cheongdae (CD), and Y0148-2 and Y0148-24 from Youngha (YH). Flower width ranged 13.2~17.4mm. Flower, pollen and anther were bigger than the mother plants. Pollen germination rate of the tetraploid lines ranging 36.1~58.8% was lower than mother plants (46.5~67.6%). Self-fertilization rate in 4 varieties, MA, BL, CD and YH was low as 1.3%, 4.0%, 1.4% and 4.7% respectively indicating that mother plants are self-incompatible. Self-fertilization rate in tetraploid lines was higher as 58.1~87.5% and B0148-43, M0148-120, and D0148-72 showed the highest self-fertilization rate over 80%. Conclusion : Tetraploid lines showed higer self-fertilization rate than mother plants that they were expected as valuable resources for new boxthorn variety having self-compatibility.
        444.
        2016.05 서비스 종료(열람 제한)
        Background : Tetraploid plant is bigger in size of organs like leaf, stem, fruit, and root than diploid plant by chromosome doubling. Also, Self-ìncompatibílity disappeares and disease resistance is strengthened in tetraploid plant. To breed new boxthorn variety having bigger fruit, higher yield, pest tolerance, and, self-compatibílity, tetraploids was induced for tetraploid breeding resources by colchicine treatment in each boxthorn variety. Materials and Methods : Colchicine was treated in Myongan, Cheongdae, Bulro, and Youngha for 0.1% concentration and 48 hours. Polyploid was identified by flow cytomertry(Partec, PA-1) and chromosome numbers of polyploid individuals were examined by aceto-carmine stain. Conclusion : Colchicine was treated in Myongan, Cheongdae, Bulro, and Youngha for 0.1% concentration and 48 hours. Tetraploid was induced as 13, 9, 6, and 5 individuals in Myongan, Cheongdae, Bulro, and Youngha respectively by above colchicine treatment.
        446.
        2016.05 서비스 종료(열람 제한)
        Background : Yam absorbs nutrition and water through water absorptive root generated from head of rhizome. Round-shaped yam (RSY, Dioscorea opposita) and tropical round-shaped yam (TRSY, Dioscorea alata)are more sensitive to drought because of shorter head of rhizome and shallower root compared to long yam or short yam. This study was conducted to elucidate the effect of irrigation on RSY and TRSY yam at 205 in Institute of Bioresources Research, GBARES. Methods and Results : Tuber of RSY and TRSY were cut as 40 g, and dust-coating sterilized with lime. Seedlings were grown in heating wire installed seed bed from 25. March to 16. April. Experimental field were fertilized 2,000 kg compost, 34 kg N2, 28 kg P2O5, and 28 kg K2O. All amount of compost and P2O5 treated as basal fertilizer. N2 and K2O treated 14 and 10 kg of basal fertilizer, and 20 and 18 kg of additional fertilizer, respectively. Tillage, installation of drop-watering tapes, and covering black PE film with 60×25 cm spacing holes on 120 cm row were conducted. 20 L per m2 was irrigated 7 days interval except rainy day from middle of May to late of September. RSY had high emergence rate in early stage due to irrigation, while TRSY had no difference. Irrigation was not effective on total number of tuber but number of marketable tuber (over 200 g). Marketable tuber yield of RSY according to irrigation was increased 89% as 1,147 kg per 10 a. And tuber with irrigation was 73 g heavier. Tuber yield and marketable tuber yield of TRSY as affected by irrigation were respectively 2,611 and 1,715 kg per 10 a compared to control, 1,462 and 428 kg. And irrigated tuber was 66 g heavier. Conclusion : TRSY had more effective on irrigation than RSY. Both of yam had significant increased marketable tuber yield due to irrigation. Therefore RSY and TRSY are necessarily irrigated because of those absorptive characteristics, short head of tuber and shallow root.
        447.
        2015.12 KCI 등재 서비스 종료(열람 제한)
        In this study, the inhibitory activities of fifty plant extracts on IgE-mediated degranulation in the rat basophilic leukemia cell line (RBL-2H3 cells) were measured; the release of interleukin (IL)-4 and β-hexosaminidase from IgE-sensitized cells treated with the plant extracts was measured; and the effects of the plant extracts on cell viability were tested. The results of the analysis of plant extracts at 20 ㎍/㎖, including the aerial part of Magnolia sieboldii K. Koch, exhibited suppressive activities upon the release of IL-4. Furthermore, several plant extracts including methanol extracted from Lindera erythrocarpa Makino (aerial part) at the same concentration significantly inhibited the release of β-hexosaminidase. Twenty-six of the plant extracts, including methanol extract of Weigela subsessilis (Nakai) L. H. Bailey (branch), showed a cell proliferation effect of over 80% at 100 ㎍/㎖. In conclusion, the results suggest that the leaf/stem of Geum japonicum Thunb. and the stamen/ovary of Nelumbo nucifera Gaertn., which exhibited effective inhibition on β-hexosaminidase release and IL-4 release from mast cells and showed high cell viability, could be useful candidates as anti-allergy materials.
        448.
        2015.12 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Insects have gained increasing attention as an alternative protein and nutrient rich food source for humans. This study was conducted to investigate the physicochemical characteristics and harmful components of edible crickets (Gryllus bimaculatus) in the 6 districts of Yeonggwang (YG), Jeongseon (JS), Wonju (WJ), Hwaseong (HS), Geochang (GC), and Chungju (CJ). The average crude protein and crude lipid contents on a dry basis were 64.34% and 16.60%, respectively. The crude protein content of CJ was the highest (67.40%), whereas YG (59.42%) had the lowest content. On the other hand, the crude fat content of YG was the highest (20.61%), whereas CJ (14.04%) had the lowest content. The unsaturated fatty acid contents were 57.97-63.93 g/100 g of the total fatty acid content in the crickets of the 6 districts. The major fatty acids of the crickets in the 6 districts were palmitic acid, oleic acid, and linoleic acid. Among the essential amino acids, valine, leucine, and lysine were the most abundant. GC had the highest total amino acids (57.93 g/100 g), whereas YG (48.65 g/100 g) had the lowest. Major mineral contents included potassium (K, 0.92~1.01 mg/100 mg) and phosphorus (P, 0.74~0.88 mg/100 mg). The mineral composition was fairly similar among the crickets. Crickets in the 6 districts were verified to have safe levels of residual heavy metals according to the Korea Food & Drug Administration (KFDA) advisory levels.
        449.
        2015.11 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        Waste treatment technology for the separation and solidification of radioactive nuclides generated from the pyrochemical process has been intensively studied to achieve the reduction of radioactive waste volume. The present study reports the separation efficiency of group II fission products in LiCl waste salt generated from a electrolytic reduction process through a layer- melt crystallization method using Sr and Ba nuclides as a surrogate material of group II fission products. The concentrated group II nuclides are converted into stable oxide form in consideration of solidification by a conversion/distillation process, where selective oxidation of group II nuclides proceeds by Li2O oxidant and residual salts are removed by a vacuum distillation process. Finally, to immobilize separated group II nuclides, a preliminary solidification study was conducted using SiO2-B2O3-Al2O3 matrix, and high density glass-based waste form was fabricated under 50wt% waste loading of strontium oxide surrogate material. Through the verification of the crystallization, conversion/distillation, and solidification processes, the treatment flow for the separation and solidification of group II fission products in LiCl waste salt has been established.
        451.
        2015.07 서비스 종료(열람 제한)
        Grain weight is the most important target not only as a major component of grain yield, but also of the cooking qualities in rice breeding program. In a previous study, a high-resolution physical map targeting a cluster of yield-related QTLs for grain weight, spikelets per panicle has been constructed using series of BC3F4 nearly isogenic lines (NILs) derived from a cross between the Korean japonica cultivar Hwaseong and O. rufipogon. The QTLs including grain weight trait have been mapped in a 25.5kb region containing three genes. Based on GenBank database, these genes include male sterility 5 (OsMs5, LOC_Os09g36740), similar ascorbate peroxidase (OsApx, LOC_Os09g36750) and glutelin family protein (OsGlu, LOC_Os09g36760). Their endogenous expression patterns were analyzed in various rice tissues (2-week seedling, flag leaf, root and panicle) from the parental lines, Hwaseong and NIL-gw9. Semi-quantitative RT-PCR and qRT-PCR were performed using gene specific primer sets. The cDNAs of the similar OsApx gene of Hwaweong and NIL-gw9 were cloned. Over-expression and RNAi knock-down transgenic plants using three genes are under construction for the functional characterization of the genes. The results will be discussed.
        452.
        2015.07 서비스 종료(열람 제한)
        96 BC3F5 introgression lines derived from a cross between Hwaseong and O. rufipogon were genotyped with 131 simple sequence repeat (SSR) markers to identify and characterize quantitative traits loci (QTLs) associated with grain quality traits in rice. 96 BC3F5 lines displayed a wide range of variation for days to heading and agronomic traits. Results indicated that one major QTL (qDTH6) on chromosome 6 was associated with significant variation for days to heading. 83 lines without the O. rufipogon segment at qDTH6 were selected and analyzed for grain quality traits. QTL analysis was conducted for two groups, 96 and 83 introgression lines, and a total of 25 QTLs were detected for rice quality traits. 16 QTLs were detected in a group of 93 lines, 11 QTLs detected in a group of 83 lines, and 2 QTLs were commonly identified in both groups. Most of the QTLs detected in this study were located on the same or adjacent regions as those reported by the previous studies, and the wild alleles negatively affected quality traits. In contrast, the wild allele at qGCR9 for the glossiness of cooked rice on chromosome 9 contributed to an increase in glossiness which is positively correlated with rice eating quality. Three ILs with the wild allele at qGCR9 displayed better eating quality than the recurrent parent, Hwaseong. To confirm the effect of qGCR9, high density mapping of the qGCR9 with a series of NILs will be conducted.
        453.
        2015.07 서비스 종료(열람 제한)
        Drought stress is one of the major stresses affecting growth and productivity in rice. Drought tolerance is a complex trait governed by quantitative trait loci(QTLs) making it difficult to understand mechanisms underlying it. We generated a set of 55 introgression lines via backcrosses using Milyang23, the Korean Tongil-type rice variety as the recurrent parent and Oryza glaberrima (IRGC Acc. No. 103544) as a donor parent. 139 SSR markers were used to genotype 55 introgression lines. The 55 introgression lines with Milyang23 were evaluated for physiological traits such as fresh shoot weight (FSW), fresh root weight (FRW) and dry shoot weight (DSW) under the control and 30% PEG-treated condition. Three lines (IL9, IL12, and IL55) showing significant difference with Milyang23 were selected for further analysis. Genotyping revealed that three lines had four, four and two O. glaberrima homozygous segments, respectively. IL9 performed better than Milyang23 in all traits measured in the 30% PEG-treated condition. IL9 possessed four O. glaberrima introgressions on chromosomes 1, 2, 6 and 7. IL12 performed better than Milyang23 in FSW and FRW and contains four O. glaberrima introgressions on chromosomes 3 and 6. IL55 contains two O. glaberrima introgressions on chromosomes 2 and 6. Three lines shared the O. glaberrima segment delimited by markers RM133-RM225 at chromosomes 6. This region corresponds to the QTL region for drought tolerance reported by other previous studies. Although IL9 and IL12 showed improved drought tolerance at the seedling and vegetative stage, they performed poor under the drought stress at the reproductive stage implying that the level of drought tolerance differs according to the growth stage in rice. IL55 was not significantly different from Milyang 23 in SPP and FER and had significantly higher no. of the total grain than Milyang 23. This result seems to indicate that IL55 will be a good resource for drought tolerance breeding. The population would be useful not only in developing drought tolerant lines in the breeding program but also in fine-mapping the genes/QTLs for drought tolerance.
        454.
        2015.07 서비스 종료(열람 제한)
        Plants strictly regulate the uptake and distribution of Zinc (Zn), which is essential for growth and development. Arabidopsis thaliana plant cadmium resistance 2 (AtPCR2), a protein containing a placenta-specific 8 domain (PLAC8), is specifically expressed in the vascular tissue and epidermis of roots and is thought to act as a Zn efflux transporter (Song et al. 2010). Proteins containing PLAC8 domain function as major organ size regulators in Solanum lycopersicum and Zea may, and putative metal ion transporters in Arabidopsis thaliana, Oryza sativa and Brassica juncea. But, there are no reports which showed that the protein containing PALC8 have the function both of seed size regulation and metal homeostasis. In our study, we found that plant cadmium resistance 1 (PCR1) influences on both Zn accumulation and grain weight in rice. The expression of OsPCR1 is elevated in developing seeds of introgression line for GW2, which encodes a protein known to regulate grain weight. Grain weight of OsPCR1 knockout and knockdown lines decreased than the wild type, while OsPCR1 overexpression lines produced heavier grains. Furthermore, the grains of OsPCR1 knockdown lines exhibited substantially higher Zn and lower Cd concentrations than the control. We identified some variation in the OsPCR1 amino acid sequence between the japonica and indica rice types using 15 different rice varieties. Japonica-type PCR1 had a shorter N-terminus than did PCR1 in the other rice types. Furthermore, japonica-type grains accumulated less Zn than did indica-type grains. Our study suggests that rice PCR1 maintains metal ion homeostasis and grain weight and might have been selected for during domestication.
        458.
        2015.05 서비스 종료(열람 제한)
        This study aimed to completely remove adhered mortar from recycled aggregate (RA) using microwave irradiation (700 W) and mixed solution of hydrochloric acid (HCl) and hydrogen peroxide (H2O2). The optimum condition was first to soak RA in tap water for 30 min and then RA was soaked in mixed solution of 30% HCl and 15% H2O2 (HCl : H2O2 = 1 : 2) for 70-90 min after 15-min microwave irradiation. Therefore, the mortar of RA in the condition was completely removed within 2.3 hrs. Reaction rate (k) with the condition was –0.6408 hr-1, which was about 190 times faster than that with HCl only (k = -0.0032 hr-1).
        459.
        2015.03 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        I investigated a method for drawing the star chart in the planisphere Cheonsang-yeolcha-bunyajido. The outline of the star chart can be constructed by considering the astronomical information given in the planisphere alone and the drawing method described in Xin-Tangshu; further the chart can be completed by using additional information on the shape and linking method of asterisms out of an inherited star chart. The circles of perpetual visibility, the equator, and the circle of perpetual invisibility are concentric, and their common center locates the Tianshu-xing, which was defined to be a pole star in the Han dynasty. The radius of the circle of perpetual visibility was modified in accordance with the latitude of Seoul, whereas the other circles were drawn for the latitude of 35°, which had been the reference latitude in ancient Chinese astronomy. The ecliptic was drawn as an exact circle by parallel transference of the equator circle to fix the location of the equinoxes at the positions recorded in the epitaph of the planisphere. The positions of equinoxes originated from the Han dynasty. The 365 ticks around the boundary of the circle of perpetual invisibility were possibly drawn by segmenting the circumference with an arc length instead of a chord length with the ratio of the circumference of a circle to its diameter as accurate as 3.14 presumed. The 12 equatorial sectors were drawn on the boundary of the star-chart in accordance with the beginning and ending lodge angles given in the epitaph that originated from the Han dynasty. The determinative lines for the 28 lunar lodges were drawn to intersect their determinative stars, but seven determinative stars are deviated. According to the treatises of the Tang dynasty, these anomalies were inherited from charts of the period earlier than the Tang dynasty. Thus, the star chart in Cheonsang-yeolcha-bunyajido preserves the old tradition that had existed before the present Chinese tradition reformed in approximately 700 CE. In conclusion, the star chart in Cheonsang-yeolcha-bunyajido shows the sky of the former Han dynasty with the equator modified to the latitude of Seoul.
        460.
        2014.09 KCI 등재 SCOPUS 서비스 종료(열람 제한)
        In this paper, we report the analysis of Korean historical records on the periodic Halley’s comet according to the period (i.e., the Three Kingdoms, Goryeo Dynasty, and Joseon Dynasty) using various sources such as the Samguksagi (The History of the Three Kingdoms), Goryeosa (The History of the Goryeo Dynasty), and Joseonwangjosillok (The Annals of the Joseon Dynasty). With regards to the apparition time of the comet for each return, we referred to the works of Kronk. For the Three Kingdoms period, we could not find any record relevant to Halley’s comet from the Samguksagi. Furthermore, we examined the suggestion that the phenomenon of “two Suns” which appeared on April 1, 760 (in a luni-solar calendar), as recorded in the Samgukyusa (The Legends and History of the Three Kingdoms), indicates an instance of the the daytime appearance of Halley’s comet. In contrast with the Three Kingdoms period, we found that all returns of Halley’s comet are recorded during the Goryeo Dynasty, although others have questioned some accounts. We also found that the appearance of Halley’s comet in 1145 is mentioned in a spirit-path stele made in 1178. For the Joseon Dynasty period, we found that all apparitions of the comet are recorded, as with the Goryeo Dynasty, except for the return of 1910, at which time the former dynasty had fallen. In conclusion, we think that this study will be helpful for understanding Korean historical accounts on Halley’s comet.