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        검색결과 75

        44.
        2016.10 구독 인증기관·개인회원 무료
        A study was conducted to determine the rheological properties of gochujang and chogochujang at different temperatures (25, 35 and 45°C). The rheological properties of the samples were determined using a rotational rheometer at a shear range of 1 to 40 s-1. The gochujang and chogochujang were found to be Non-Newtonian fluids following the Herschel-Bulkley model. The yield stress and consistency coefficient of the gochujang at different temperatures were higher than those of the chogochujang but the opposite was observed for the flow behavior index. Moreover, all rheological properties of the gochujang and chogochujang decreased with increasing temperature. The consistency coefficient was related to temperature using an Arrhenius-type relationship. The gochujang (14.48 kJ/mol) has higher activation energy than the chogochujang (14.03 kJ/mol). The yield stress values of the gochujang and chogochujang can be related to temperature by linear regression equations and the flow behavior index values by exponential regression equations.
        45.
        2016.04 구독 인증기관·개인회원 무료
        The feasibility of incorporating licorice powder (LP) as a value-added food ingredient into convenient food products was investigated using yanggaeng as a model system. LP was incorporated into yanggaeng at amounts of 0, 2, 4, 6, and 8% (w/w) based on total weight of cooked white beans and LP. pH level decreased while moisture content and soluble solid content increased significantly with increasing levels of LP (P<0.05). In terms of color, lightness decreased while redness and yellowness increased significantly (P<0.05) with increasing levels of LP. Hardness also decreased significantly with higher amount of LP in the formulation (P<0.05). 2,2’-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) and 1,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities were significantly elevated by LP addition, and they increased significantly as LP concentration increased in the formulation (P<0.05). Finally, consumer acceptance test indicated that the highest levels of LP incorporation (8%) had an adverse effect on general consumer preferences. In contrast, yanggaeng with moderate levels of LP (2%) is recommended based on its overall scores to take advantage of the antioxidant properties of LP without sacrificing consumer acceptability.
        46.
        2016.04 구독 인증기관·개인회원 무료
        Brachymystax lenok tsinlingensis (family Salmonidae), cold freshwater fish, is endemic to Asia. This species is currently distributed throughout Russia, Mongolia, China and the Korean Peninsula. B. lenok tsinlingensis in South Korea was severely affected by anthropogenic activities such as habitat destruction, agricultural run-off and water pollution, and hence this fish has recently been dramatically decreased in its population sizes and become now critically endangered. To recover the number of individuals of B. lenok tsinlingensis, stocking or translocation programs have been conducted continuously by local governments since 1970s. However, these programs made little effort to clarify populations that may have originated from stocked, translocated or introduced fish. An understanding of genetic characteristics of endangered populations is critical to develop effective conservation and restoration plans especially because genetic diversity ensues their future fate. Therefore, we assessed the “conservation status” of this species by estimating the level of genetic diversity and genetic structure among ten geographic populations including restored populations via reinforcement and supplementation. Also, we aimed to trace the genetic origins of the newly translocated population (Chiak) through a restoration practice program. Moreover, we inferred the phylogenetic relationships among Korean lenok populations as well as across the Northeast Asia. Two hundred eighteen individuals of B. lenok tsinlingensis were sampled from ten localities (Yanggu, Injae, Seorak, Bangtae and Hongcheon: North Han River basin; Pyeongchang, Chiak and Jeongseon: South Han River basin; Taebaek and Bonghwa: Nakdong River basin in South Korea). Based on mitochondrial DNA (mtDNA) control region and eight nuclear microsatellite loci, we found extremely low levels of within-population genetic diversity, which suggests small effective population sizes (Ne) within populations. For mtDNA control region, each population housed one, or at most, two haplotypes that are restricted to the respective localities, meaning that these ‘genetically unique’ lineages will be lost permanently if the local populations undergo extinction. The overall values of haplotype diversity (h) and nucleotide diversity (π) for the entire Korean population were 0.703 ± 0.024 and 0.021 ± 0.010, respectively. In the case of microsatellites, average number of alleles across the eight loci for the entire population was 9.1 and allelic richness (AR) per population ranged from 2.375 to 4.144 (mean = 3.104). The values of observed heterozygosity (HO) and expected heterozygosity (HE) were similar to each other [HO: 0.400 ~ 0.590 (mean = 0.518); HE: 0.407 ~ 0.608 (mean = 0.504)]. The inbreeding coefficient (FIS) values were generally low, ranging from 0.048 to 0.279. Consequently, the majority of the populations (except Yanggu and Pyeongchang) were not significantly deviated from Hardy-Weinberg equilibrium (HWE), suggesting random mating at these loci tested. In addition, we found that Korean lenok populations were significantly genetically isolated from each other, with private mtDNA haplotypes and microsatellite alleles, indicating limited gene flow among populations, strong effects of genetic drift due to small Ne, or a combination of both. The Mantel test of microsatellites revealed a significant correlation (r = 0.414, P = 0.04) between genetic and geographic distances for pairwise comparisons among the ten populations, while that of mtDNA showed a lack of correlation. Given the shared identical mtDNA haplotype and similar microsatellite allelic distributions between Chiak and Hongcheon populations, we suggest that the restored (introduced) Chiak population would be inferred to be genetically originated from Hongcheon population. Phylogenetic relationships among Northeast Asian populations showed that South Korean lineages have more recently diverged from China (Yellow River), than between North Korea and Russia. Although the phylogenetic relationship would be expected to be associated with geography, South-North Korea and China populations with a similar latitude was more phylogenetically closely related. These findings may suggest a possible scenario for the historical movements of B. lenok tsinlingensis in Northeast Asia during Last Glacial Maximum (LGM). It would be supported by the line of evidence that most lenok populations migrated to southward from Northern Asia such as Russia and Mongolia during LGM because the Korean Peninsula was landlocked as inland epoch and functioned as a southern shelter with Yellow River. For this reason, the Korean Peninsula is suggested to be an important geographical region for better understanding phylogenetic relationships and evolutionary histories of B. lenok tsinlingensis across the Northeast Asia. Despite large efforts made to develop several restoration programs in South Korea for B. lenok tsinlingensis, it is still unknown whether these past restoration efforts were successful or fruitless, mainly because of little attention paid to post-restoration monitoring research. Hence, there was a lack of their published official records. In the future, conservation and restoration projects of the Korean lenok populations should consider the genetic data for a better understanding of their ecological and evolutionary trajectories. And finally, we hope that our findings here can help inform on the future effective conservation and restoration plans for B. lenok tsinlingensis populatio ns in South Korea.
        48.
        2014.10 구독 인증기관·개인회원 무료
        The oedemerid species Oedemera sexualis Marseul, 1877 is reported for the first time from Korea. The genus Oedemera Olivier, 1789, within subfamily Oedemerinae and family Oedemeridae, is one of the common oedemerid beetles being widely distributed throughout the world. The world-widespread genus Oedemera is presented 3 subgenera and 104 species in Palaearctic region. Until now, 8 species and subspecies were recorded in Korea. O. sexualis was found in Is. Yongcho and Is. Bijin in Tongyeong-si, Gyeongsangnamdo of Korea, bringing the number of Korean Oedemera species to 9 species. In this study, we report the taxonomic key to the genus Oedemera of Korea, and morphological description of O. sexualis.
        49.
        2014.06 구독 인증기관 무료, 개인회원 유료
        Despite many researches related with in-vitro culture of porcine spematogonial stem cells (SSCs), adherent culture system widely used has shown a limitation in the maintenance of porcine SSC self-renewal. Therefore, in order to overcome this obstacle, suspension culture, which is known to have numerous advantage over adherent culture, was applied to the culture of porcine SSCs. Porcine SSCs retrieved from neonatal testes were suspension-cultured for 5 days or 20 days, and characteristics of suspension-cultured porcine SSCs including proliferation, alkaline phosphatase (AP) activity, and self-renewal-specific gene expression were investigated and compared with those of adherent-cul-tured porcine SSCs. As the results, the suspension-cultured porcine SSCs showed entirely non-proliferative and significantly higher rate of AP-positive cells and expression of self-renewal-specific genes than the adherent-cultured porcine SSCs. In addition, long-term culture of porcine SSCs in suspension condition induced significant decrease in the yield of AP staining-positive cells on post-day 10 of culture. These results showed that suspension culture was inappropriate to culture porcine SSCs, because the culture of porcine SSCs in suspension condition didn’t stimulate proliferation and maintain AP activity of porcine SSCs, regardless of culture periods.
        4,000원
        50.
        2014.04 구독 인증기관·개인회원 무료
        Nitidulid beetles of the genus Aethina Erichson, 1843 are a well-known group as harmful to agricultural and apicultural industry, especially including A. tumida, an American small hive beetle, which is a beekeeping pest. The world-widespread genus Aethina, within subfamily Nitidulinae and family Nitidulidae, is presented 5 subgenera and 28 species in Palaearctic region. Until now, 2 subgenera, Aethina s. str. and Aethina (Circopes), and 3 species, A. (A.) flavicollis, A. (A.) inconspicua and A. (C.) suturallis, have been recorded in Korea, and we added one more species, A. (A.) maculicollis as a newly recorded species. The larvae of A. (A.) maculicollis have been reported as pests of mulberry fruits in Japan. In this study, we report the taxonomic key to the genus Aethina of Korea, and morphological description of A. (A.) maculicollis.
        51.
        2013.04 구독 인증기관·개인회원 무료
        Olibrus Erichson, 1845 and Olibrus particeps Mulsant & Rey, 1861 (Coleoptera: Cucujoidea: Phalacridae) are reported from Korea for the first time and historical review of the taxonomic position of this genus is provided. The genus Olibrus Erichson is one of the common phalacrid beetles being widely distributed throughout the world. This genus is easily distinguished from other phalacrid genera by combination of the following characters: Antennae inserted at sides of front, base visible from above; Last segment of antenna softly indented; Basal metatarsomere shorter than second; Elytral surface very polished. O. particeps was found in Andong-si and Yeongju-si, Gyeongsangbuk-do of Korea, bringing the number of species within the Korean Phalacridae to 2 species. In this study, we provide a redescription of O. particeps Mulsant & Rey, and illustrations of its genitals and other appendages.
        52.
        2012.06 구독 인증기관·개인회원 무료
        In the present study, we investigated the effect of porcine follicular fluid (PFF) concentration (10% vs. 1%) and protein-free media (PFF 0%) on maturation of porcine oocytes in vitro and analysed difference in gene expression in resulting blastocysts following parthenogenetic activation. Three groups were tested; 1) 10% PFF: Tissue culture medium (TCM) 199+10% PFF; 2) 1% PFF: TCM 199+1% PFF; and 3) 0.1% PVA: TCM 199+0.1 PVA. Cumulus-oocyte-complexes were cultured in the respective media containing gonadotrophin (1 ug/ml), epidermal growth factor (10 ng/ml), cystein (0.57 mM), sodium pyruvate (0.91 mM), insulin (5 ug/ml), 9-cis retinoic acid (5 nM) for 20~22 h and then without hormonal supplements for an additional 20-22 h. Data was analyzed using statistical analysis system(SAS) program. There was no significant difference in oocyte maturation rate. However, significantly higher (p<0.05) proportions of embryos developed to the blastocyst stage when oocytes were matured in 10% PFF group (45%) than in the 1% PFF group (31.1%). The total cell numbers were not significantly different among groups (52 ± 1.3 vs. 54.6±3.1 vs. 54.4±2.5, respectively). The relative abundance (ratio to beta-actin mRNA) of gene transcripts related to apoptosis in blastocysts was measured by real- time PCR. The expression of anti-apoptotic gene (BclxL) was up-regulated and the expression of pro-apoptotic gene (Bax) was down-regulated in 10% PFF group than in the other groups. Therefore, it can be concluded that supplementation of 10% PFF during in vitro maturation improves embryo development by reduction of apoptosis. * This study was supported by IPET (#311011-05-1-SB010), RNL Bio (#550-20120006), MKE (#10033839-2011-13), Institute for Veterinary Science, the BK21 program and TS Corporation.
        53.
        2012.06 구독 인증기관·개인회원 무료
        Embryo transfer (ET) is the final procedure for getting pregnancy through assisted reproductive technology such as IVF (in vitro fertilization), SCNT (somatic cell nuclear transfer). In our laboratory, the porcine cloned embryos loaded in ET medium are carried for 3 hours by portable incubator because of the great distance from the laboratory to the experimental farm. Thus, before transferring into recipient, porcine cloned embryos are exposed in vitro condition for long time. Medium which is used in this process is the TALP (Tyrode’s medium supplemented with 10 mM HEPES), but it includes little nutrients for embryo. Thus, the aim of this study is to determine whether ET media containing nutrients affect the in vitro development of embryos compared to TALP. For the experiment, porcine zygote medium (PZM)-5 which has amino acids for developing embryo was chosen as ET medium containing nutrients, added 10 mM Hepes as PZM-5 does not contain buffering system. For experiment, we carried out parthenogenesis through a chemical method using Thi/DTT. Parthenogenetic embryos were cultured in PZM-5 for 2 days, and then they were randomly divided into two group; loaded in a straw with TALP or PZM-5-Hepes, respectively. They were stored in a portable incubator for 3 hours to simulate the time consumed in ET, thereafter embryos in both TALP and PZM-5-Hepes groups were respectively cultured in PZM-5 for additional 5 days. All experiments were repeated 5 times. In result, blastocyst formation rate were 22.46%±1.47 and 23.17%± 2.13, respectively and total cell number were 32.9±2.22 and 37.09±2.18, respectively. There is no significant difference between TALP and PZM-5-Hepes groups. * Further study will investigate effect of PZM-5-Hepes on in vivo development of porcine cloned embryo. This study was supported by IPET (#311011-05-1-SB010), RNL Bio (#550-20120006), Institute for Veterinary Science, the BK21 program and TS Corporation.
        54.
        2012.06 구독 인증기관·개인회원 무료
        Adipose tissue-derived mesenchymal stem cells (ASCs) are very interesting in several laboratory animals and humans because they are easy to harvest and expand to generate millions of cells from a small quantity of fat. ASCs are known as useful materials for clinical applications in human cell therapy and as a donor cell in somatic cell nuclear transfer (SCNT). Here, we investigated if 1) minipig ASCs can be isolated, self-renewed and differentiated into multiple tissue lineages, 2) ASCs can be a suitable donor cell type for generation of cloned pig. In order to isolate ASC, adipose tissues were collected from inguinal region of a 6-year-old female minipig. The ASCs were attached to the culture dish with a fibroblast-like morphology. They expressed cell-surface marker characteristics of stem cell, underwent osteogenic, adipogenic, myogenic, neurogenic and chondrogenic differentiation when exposed to specific differentiation-inducing conditions. To investigate its potential as donor cell for cloning, we respectively carried out SCNT using ASC, adult skin fibroblast (ASF) and fetal fibroblast (FF) derived from same minipig. The ratio of blastocysts to 2-cell embryos and total cell number of blastocysts were monitored as experimental parameters. In results, cleavage and developmental competence to blastocysts rate showed no significant difference among the three groups. On the other hand, total cell numbers of blastocysts derived from ASC and FF were significantly higher than in ASF (89±7.9 and 105±5.5 vs. 57.5±5.2, respectively). Our results demonstrated that ASC have potential compared to ASF and FF in terms of the in vitro development and blastocyst formation ability. In further study, we will investigate the in vivo developmental ability of ASC as donor cell for pig cloning. * This study was supported by IPET (#311011-05-1-SB010), RNL Bio (#550-20120006), Institute for Veterinary Science, the BK21 program, TS Corporation and Optifarm Solution.
        56.
        2008.10 구독 인증기관·개인회원 무료
        The genus Linaeidea Motschulsky, 1860, contains six species, and is distributed in China, Japan, USSR, Europe, with only two species known in Korea (Gressitt and Kimoto, 1963; Seeno and Wilcox, 1982; Kimoto and Takizawa, 1994; Lee and An, 2001). Morphological notes of the immature stages and life history of Japanese L. aenea (Linne, 1758) were well studied by Kimoto (1962)and Kimoto and Takizawa (1994). Very little is known about the immature stages of this genus from Korea: only the larva of L. aenea have been briefly described and illustrated by Lee (1996). According to Hennig (1938), this genus is separable from the genus Chrysomela, in having sternal tubercles which are disappeared in the last instar larvae. However, the L. adamsi was not applied in the diagnosis character of this genus. The purpose of this results are to provide a key, detailed description, illustration and tubercles patterns of all known Korean species of genus Linaeidea as the basic data for the phylogenetic study the subfamily Chrysomelinae.
        58.
        2007.03 구독 인증기관 무료, 개인회원 유료
        The present study investigated the effects of follicle stimulating hormone (FSH) and human chorionic gonadotrophin (hCG) on the nuclear maturation of canine oocytes. Oocytes were recovered from mongrel female ovaries in various reproductive states; follicular, luteal or anestrous stage. Oocytes were cultured in serum-free tissue culture medium (TCM)-199 supplemented with various concentrations of FSH (Exp. 1: 0, 0.5, 1.0 or 10 IU) or hCG (Exp. 2: 0, 0.5, 1.0 or 10 IU) or both (Exp. 3: 1 IU FSH + 1 IU hCG) for 72 hr to determine the effective concentration of these hormones, and to examine their combined effect. After maturation culture, oocytes were denuded in PBS containing 0.1% (w/v) hyaluronidase by gentle pipetting. The denuded oocytes were stained with 1.9 μM. Hoechst 33342 in glycerol and the nuclear state of oocytes was evaluated under UV light. More (p<0.05) oocytes matured to MII stage when follicular stage oocytes were supplemented with 1 IU FSH (6.2%) compared with the control, 0.1 or 10.0 IU FSH (0 to 1.2%). Significantly higher (p<0.05) maturation rate to MII stage was observed in follicular stage oocytes supplemented with 1.0 IU hCG (7.2%) compared with the control or other hCG supplemented groups (0 to 1.5%). However, the combination of FSH and hCG did not improve the nuclear maturation rate of canine oocyte (2.4 %) compared with FSH (6.2%) and hCG alone (7.2%). In conclusion, FSH or hCG alone significantly increased the maturation of canine oocytes to MII stage.
        4,000원
        59.
        2005.12 KCI 등재 SCOPUS 구독 인증기관 무료, 개인회원 유료
        중저준위 방사성폐기물 천층처분시설의 처분덮개설계 및 성능평가를 위해 국내 역사시대 고분연구를 수행하였다. 처분덮개 성능과 관련된 국내외 연구현황을 조사하고 삼국시대 고분을 중심으로 봉분의 층상특성을 정리하였다. 국내 고분에 대한 봉토의 시료채취와 시료에 대한 수리전도도 측정 및 분석을 실시하였다. 고분에 대한 자연유사 연구에서 발굴조사보고서 상에 제시된 봉토의 유사판축기법의 적용, 모세관 방벽현상과 배수로를 이용한 봉분 내 습도조절 여부를 천층처분 시설설계에 활용할 수 있을 것으로 판단된다. 향후 국내 고분발굴현장이 있을 때 현장을 방문하여 필요한 자료수집과 더불어 원자력분야의 관심사와 필요사항에 대하여 국내 고고학계와의 정보교환이 이루어져야 할 것으로 판단된다.
        4,500원
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