검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 82

        41.
        2017.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Porcine spermatogonial stem cells (SSCs) prefer three-dimensional (3D) culture systems to 2D ones for the maintenance of self-renewal. Of the many 3D culture systems, agar-based hydrogels are candidates for supporting porcine SSC self-renewal, and there are various types of agar powder that can be used. In this study, we sought to identify an agar-based 3D hydrogel system that exhibited strong efficacy in the maintenance of porcine SSC self-renewal. First, 3D hydrogels with different mechanics were prepared with various concentrations of Bacto agar, lysogeny broth (LB) agar, and agarose powder, and the 3D hydrogel with the strongest alkaline phosphatase (AP) activity and greatest increase in colony size was identified for the different types of agar powder. Second, among the porcine SSCs cultured in the different 3D hydrogels, we analyzed the colony formation, morphology, and size; AP activity; and transcription and translation of porcine SSC-related genes, and these were compared to determine the optimal 3D hydrogel system for the maintenance of porcine SSC self-renewal. We found that 0.6% (w/v) Bacto agar-, 1% (w/v) LB agar-, and 0.2% (w/v) agarose-based 3D hydrogels showed the strongest maintenance of AP activity and the most pronounced increase in colony size in the culture of porcine SSCs. Moreover, among these hydrogels, the strongest transcription and translation of porcine SSC-related genes and largest colony size were detected in porcine SSCs cultured in the 0.2% (w/v) agarose-based 3D hydrogel, whereas there were no significant differences in colony formation and morphology. These results demonstrate that the 0.2% (w/v) agarose-based 3D hydrogel can be effectively used for the maintenance of porcine SSC self-renewal.
        4,000원
        42.
        2017.11 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The relationship of in vitro starch digestibility and gel strength was investigated at various concentrations (10-30%) of rice cultivars with different amylose contents (27.9, 17.9, and 5.2%). As the rice flour concentration increased, predicted glycemic index decreased, but gel strength increased regardless of amylose contents. Gel strength correlated strongly with amylose content, whereas in vitro starch digestibility was more highly affected by rice flour concentration than by amylose contents. Moreover, the impact of degree of gelatinization on in vitro starch digestibility of high amylose rice was also examined in terms of structural features and rheological properties. The digestion rate of fully gelatinized flour was 1.7 times higher than that of native flour, while the disrupted structure with a different gelatinization degree during starch digestion was visually demonstrated through the X-ray diffraction and molecular distribution analysis. The rice flour changed from an A-type to a V-type pattern and showed difference in crystalline melting. The low molecular weight distribution increased with increasing degree of gelatinization during starch digestion. The apparent viscosity also increased with degree of gelatinization. These results demonstrated that the starch digestibility of rice was more affected by concentration than by amylose content, as well as by the degree of gelatinization due to structural difference.
        4,000원
        43.
        2017.10 구독 인증기관·개인회원 무료
        The members of the genus Flavivirus are noteworthy, as they cause infectious diseases in humans, such as Zika, denguefever, yellow fever, West Nile, and Japanese encephalitis. Due to the increased awareness of the public health risk posedby flavivirus-infected mosquitoes, mosquito collections were performed in six urban parks of South Korea, as the parksare designated for human recreation but also provide suitable habitats for mosquitoes. We examined the diversity andabundance of mosquito species and conducted molecular diagnostics for the detection of flavivirus infections. Monthlycollections were carried out in each park from March to August in 2017. A total of 4,851 mosquitoes (5 genera and13 species) were collected using BG-sentinel traps and then investigated for flavivirus infections. Pathogenic flavivirusinfections causing human diseases were not observed in the field-collected mosquitoes. However, insect-specific flavivirus(ISF) infections were detected in several mosquito pools. ISF has been previously known to enhance or suppress the replicationof medically important flaviviruses in co-infected mosquito cells. In this study, partial sequences of ISF were analyzed.However, further studies are needed in order to determine its genetic characterization and biological function in vivo.
        44.
        2017.06 구독 인증기관 무료, 개인회원 유료
        Selecting an appropriate antigen with optimal immunogenicity and physicochemical properties is a pivotal factor to develop a protein based subunit vaccine. Despite rapid progress in modern molecular cloning and recombinant protein technology, there remains a huge challenge for purifying and using protein antigens rich in hydrophobic domains, such as membrane associated proteins. To overcome current limitations using hydrophobic proteins as vaccine antigens, we adopted in silico analyses which included bioinformatic prediction and sequence-based protein 3D structure modeling, to develop a novel periodontitis subunit vaccine against the outer membrane protein FomA of Fusobacterium nucleatum. To generate an optimal antigen candidate, we predicted hydrophilicity and B cell epitope parameter by querying to web-based databases, and designed a truncated FomA (tFomA) candidate with better solubility and preserved B cell epitopes. The truncated recombinant protein was engineered to expose epitopes on the surface through simulating amino acid sequence-based 3D folding in aqueous environment. The recombinant tFomA was further expressed and purified, and its immunological properties were evaluated. In the mice intranasal vaccination study, tFomA significantly induced antigen-specific IgG and sIgA responses in both systemic and oral-mucosal compartments, respectively. Our results testify that intelligent in silico designing of antigens provide amenable vaccine epitopes from hard-to-manufacture hydrophobic domain rich microbial antigens.
        4,000원
        45.
        2017.05 구독 인증기관·개인회원 무료
        Generally, fate of spematogonial stem cells (SSCs) can be determined specifically by microenvironments enclosed with various extracellular matrix (ECM) components and integrins recognizing directly ECM proteins play an pivotal role in transporting ECM-derived signals into cytoplasm, resulting in inducing a variety of biological functions such as cell attachment, self-renewal and differentiation. However, to date, studies on type of integrins expressed on the undifferentiated SSCs remain unclear. Therefore, we tried to investigate systematically what kind of integrin subunits are expressed transcriptionally or translationally in the SSCs derived from testis of hybrid B6CBAF1 mouse. For these, isolation of SSCs from testis were conducted by magnetic activated cell sorting (MACS) using Thy1 antibody. Subsequently, transcriptional and translational level of integrin α and β subunits in the isolated SSCs were measured by real-time PCR and fluorescene immunoassay, respectively. As the results, transcriptional levels of genes encoding total 25 integrin subunits were quantified, and integrin α4, α6, α7, α9, αV, αL and αE and integrin β1, β5 showed higher expression levels than other subunits. By contrast, integrin α3, α5, α 10 and α11 and integrin β2, β3, β4, β7 were weakly transcribed. When translational levels of the integrin α subunits showing high transcription level (α4, α6, α7, α9, αV αL, and αE) were measured, integrin α6, α7, α9, αV and αL were higher than integrin α4 and αE. In case of integrin β subunit, β1 evaluated more expression than β5. From these results, we speculate that the undifferentiated SSCs derived from hybrid B6CBAF1 mouse may express integrin α4β1, α6β1, α7β1, α9β1, αVβ1 and/or αVβ5 on plasma membrane. Moreover, this information will greatly contribute to constructing non-cellular niche supporting self-renewal of SSCs in the future.
        46.
        2017.04 구독 인증기관·개인회원 무료
        A study was conducted to determine the rheological properties of pomegranate puree (PP) as affected by different gums (xanthan and guar gums) and 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 PP added with xanthan and guar gums were found to be Non-Newtonian fluids following the Herschel-Bulkley model. The yield stress and consistency coefficient of the PP with xanthan gum at different temperatures were higher than those of the PP with guar gum but the opposite was observed for the flow behavior index. Moreover, all rheological properties of the PP regardless of type of gum addition decreased with increasing temperature. The consistency coefficient was related to temperature using an Arrhenius-type relationship. The PP with xanthan gum (16.11 kJ/mol) has higher activation energy than the PP with guar gum (11.44 kJ/mol). The yield stress values of the PP with xanthan gum and guar gum can be related to temperature by linear regression equations and the flow behavior index values by exponential regression equations.
        51.
        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.
        52.
        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.
        53.
        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.
        55.
        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.
        56.
        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
        57.
        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.
        58.
        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.
        59.
        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.
        60.
        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.
        1 2 3 4 5