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        검색결과 48

        1.
        2023.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In 2022, research for native prokaryotic species in Korea reported 10 unrecorded bacterial strains affiliated to phyla Actinomycetota, Bacillota, and Pseudomonadota. The strains formed monophyletic clades with the most closely related species (with ≥98.7% sequence similarity) in the 16S rRNA gene sequencing. Among them, four species of the phylum Actinomycetota, two species of the phylum Bacillota, and four species of the phylum Pseudomonadota have not been reported in Korea, suggesting unrecorded species in Korea. Information on strains such as Gram staining reaction, colony and cell morphology, biochemical characteristics, and isolation sources were provided in the species description.
        4,000원
        2.
        2023.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The inclusion of conductive carbon materials into lithium-ion batteries (LIBs) is essential for constructing an electrical network of electrodes. Considering the demand for cells in electric vehicles (e.g., higher energy density and lower cell cost), the replacement of the currently used carbon black with carbon nanotubes (CNTs) seems inevitable. This review discusses how CNTs can contribute to the development of advanced LIBs for EVs. First, the reason for choosing CNTs as a conducting agent for the cathode is discussed in terms of energy density. Second, the reinforcing effect of CNTs on the anode is described with respect to the choice of silicon as the active material. Third, the development of water-based cathode fabrication as well as dry electrode fabrication with aid of CNTs is discussed. Fourth, three technical hurdles, that is, the price, dispersion issue, and entrapped metal impurities, for widespread use of CNTs in LIBs are discussed.
        4,000원
        3.
        2022.10 구독 인증기관·개인회원 무료
        In 2018, media reports raised issues related to radon released from building materials used as finishing materials in apartment houses. Accordingly, related ministries recommended not to use materials with a radiation index value exceeding 1. In order to calculate the radioactivity index, not only 226Ra producing radon (222Rn) but also 232Th and 40K radioactivity concentrations are required. To determine the concentration of the radionuclide, 40K is measured by a single gamma ray of 1,460.8 keV. And the 228Ac used to measure 232Th mainly utilizes gamma rays of 911.2 keV. However, 228Ac does not appear as a single peak unlike 40K, and appears as multiple peaks at various energies. Among them, gamma rays are emitted at a intensity of 0.83% at 1,459.2 keV, which is likely to interfere with 40K. Therefore, what is actually measured at 1,460.8 keV is theoretically a compound peak of 40K and 228Ac. Because the probability of emission at 1,459.2 keV (0.83%) is low, a low concentration of 232Th will result in little 40K radioactivity error. However, samples containing a high concentration of 232Th overestimate the 40K radioactive concentration, so correction is required. In this study, the IAEA standard substance (IAEA-RGTh-1) ontaining 232Th of actual high concentration was analyzed, and the results of the analysis without correction of 40K were compared and verified. As the 40K correction method, the 911.2 keV gamma-ray of 228Ac was used as the reference peak to separate the peak of 228Ac (1,459.2 keV) from the 40K (1,460.8 keV) mixed peaks. And, the coefficient value obtained by subtracting the peak of 228Ac (1,459.2 keV) from the 40K (1,460.8 keV) mixed peak was set to a pure peak of 40K and the radioactivity concentration was calculated therefrom. As a result of calculating the IAEA-RGTh-1 reference material without correction, it was confirmed that the 40K value was overestimated by about 38 times. If a measurement beyond the MDA of 40K is generated by 228Ac radioactivity because the 40K correction constant is not applied, there is an error in determining that there is 40K radioactivity. However, even if 40K radioactivity is overestimated due to the high concentration of 232Th, the degree to which this effect contributes to the radioactivity index is very small. However, as an analyst, 40K radioactivity correction should be made for more accurate analysis.
        5.
        2020.05 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The fish influx and behavioral properties at a set-net off Goseong, South Korea were investigated using an imaging sonar. As a result, the average influx of fish was 33.9% at day time and 66.1% at night time, respectively, which indicated that a majority of fish entered into a playground in the set-net at night. The fish behavioral properties such as target (fish) length, range, orientation and major-axis angle were examined and compared among survey dates (4, 5, and 6 June 2019) using the statistical analysis tool (analysis of variance, ANOVA). The behavioral properties presented differently sometime of survey dates. This is preparatory study to support fish behavior properties in a set-net. It is expected that more elaborated behavioral information of fishes in the set-net is beneficial for designing and deploying a set-net fishing gear as well as general fish behavior research in the future.
        4,000원
        6.
        2019.12 구독 인증기관 무료, 개인회원 유료
        The multilateral trade relations between Malaysia and MERCOSUR is a new market. This study focuses on automotive policy areas towards the MERCOSUR regime which focus on trade ties. The purpose of this study is to expand national automotive policy to penetrate the automotive sector in the MERCOSUR. While it create opportunities to penetrate the automotive sector in MERCOSUR where Malaysia needs to enhancement national trade performance of FTA potential within MERCOSUR regime especially on investment and trade. The main issue is the lack of progress and process are restrictions on Malaysia's within MERCOSUR in the automotive field. Malaysia does not pursue trade within respective nation but in statistical shows have a large and positive market economy with the southern continent of America, especially the automotive industry and lack of performance of Malaysian counterparts and MERCOSUR and unsuccessful automotive investment and exporters. This research uses qualitative research methods, data collection, interviews, and content analysis methods for this study. Expert from respective agencies as interviewees such as the Ministry of Foreign Affairs (MOFA), Malaysia Trade Relations Division (MATRADE), the Department of Robotics and the automotive trade policy of Malaysia and the IoT Institute. Coding techniques are used for coding processes in content analysis. Hereby, the analysis by using the Economic Integration theory with SWOT Analysis to find out the implementation of Malaysia FTA within the MERCOSUR .Hence, research findings show that Malaysia's multilateral within MERCOSUR relations have a potential to be strengthened with a variety of positive and initiatives from the Malaysia government.
        4,800원
        7.
        2019.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Many transcription factors are involved in directing the growth of porcine oocytes. The localization and expression level of a given transcription factor often differ at each stage of early embryonic growth, which spans from fertilization to the formation of the blastocyst. A hallmark of the blastocyst stage is the separation of the endodermal and mesodermal ectoderm. The embryo's medium and its effects are known to be crucial during early development compared to the other developmental stages, and thus require a lot of caution. Therefore, in many experiments, early development is divided into the quality of oocyte and cumulus cells and used in experiments. We thought that we were also heavily influenced by genetic reasons. Here, we examined the expression patterns of five key transcription factors (CDX2, OCT4, SOX2, NANOG, and E-CADHERIN) during porcine oocyte development whose expression patterns are controversial in the pig to the literature. Antibodies against these transcription factors were used to determine the expression and localization of them during the early development of pig embryos. These results indicate that the expressions of key transcription factors are generally similar in mouse and pig early developing embryos, but NANOG and SOX2 expression appears to show species-specific differences between pig and mouse developing embryos. This work helps us better understand how the expression patterns of transcription factors translate into developmental effects and processes, and how the expression and localization of different transcription factors can crucially impact oocyte growth and downstream developmental processes.
        4,000원
        8.
        2019.04 구독 인증기관·개인회원 무료
        Methyl bromide (MB) has been still routinely used in quarantine fumigation on imported citrus, although there had been issuing chronic inhalation toxicity to fumigators and related workers as well as phytotoxic damages after fumigation. Ethyl formate (EF), is the only option to replace MB in terms of its safety for consumers (food additive and naturally occurred) and worker with higher threshold level limit (TLV = 100 ppm). Its application technology also provide cost effectiveness, good commercial practice in terms of application time (< 10 min) for 40 ft container. The replacement of MB with EF is recommended not to fumigate with hazardous and phasing-out MB on imported oranges.
        9.
        2018.11 구독 인증기관·개인회원 무료
        The embryonic genome activation (EGA) is genetically activated states that embryos make the materials such as growth factors for using themselves. EGA is various because they have many materials, different site, different stage, also different species. At this time, transcription factors are expressed. Transcription factors bind to specific DNA region, and regulate the gene expression. Thus, we check the expression of transcription factors, we can know that embryo development is very well or not. The development stages of embryos are basically the stages from fertilization to blastocyst. So, we check the embryos oocyte to blastocyst. In our experiments, we focus the early developmental transcription factors such as Cdx2, Oct4, Sox2, Nanog and E-Cadherin. Above antibody factors showed different expression sites, and there were many differentiated parts from other animal species. In addition, we compared the SCNT and parthenogenetic activation (PA) because these are same methods using electrical activation among the embryo production methods. Our results showed not only similar patterns but also different patterns between pig and mouse. Therefore, we have to investigate that different patterns of transcription factors play a role in pigs, and why occur.
        10.
        2018.11 구독 인증기관·개인회원 무료
        Until now, problems related to shortage of organ for transplantation have been continuing. Pigs are the most suitable animal for xenotransplantation. Although primates are most similar to humans, they are not suitable because they have low productivity. Pigs are more productive than primates, and their organ size and physiological characteristics are similar to humans, with the exception of primates. In this study, we breeding the transgenic minipigs using natural mating to produce transgenic pigs. And, transgenic pigs has transmission rate that follow mendel’s rule. There are 20% hDAF gene, 20% US11 gene and 50% both hDAF and US11 gene in transgenic offsprings. Furthermore, transgenic pigs followed normal litter size, and piglets also has normal sex ratio. To suppress the immune function, experiments were performed using porcine ear fibroblast that transfected with hDAF and US11gene. In Cytotoxicity experiment against human complement, hDAF gene and double transgenic cell with both hDAF and US11 gene showed effect to reduce cytotoxicity rate in all of human complement condition. US11 gene and double transgenic cell were significantly reduce the cytotoxicity ratio in human NK cell. Besides, hDAF gene transgenic cell also reduce immune response in 10:1 concentration of human NK cell. In conclusion, natural mating was efficient method for breeding transgenic pigs. And, hDAF and US11 genes has effect for reduce cytotoxicity against human NK cell and human complement conditions.
        11.
        2017.10 구독 인증기관·개인회원 무료
        The antioxidant and antitumor properties of natural products, often recognized in traditional medicine systems, represent therapeutic modalities to reduce or prevent uncontrolled oxidation processes which in turn potentially ameliorate or tumor based symptoms of chronic diseases. We have studied the antioxidant and antitumor effects of Amanita muscaria (A. muscaria) in vitro and examined whether the A. muscaria has synergistic effects on antioxidant and antitumor properties. Although A. muscaria induced a dose-dependent increase in antioxidant activity, the latter has a consistently higher antioxidant effect. In mouse monocytes, the lipopolysaccharide- (LPS-) induced tumor necrosis- (TNF-) synthesis was significantly inhibited by A. muscaria in a dose dependent manner and synergistic effects were clearly demonstrated with the A. muscaria on TNF- inhibition. A. muscaria effect was also evident on inhibition of nuclear factor-kappa B activity, cyclooxygenase-II activity, and lipid peroxidation in mouse monocytes. This presented results may be a starting point for a comprehensive characterization of biological effects of A. muscaria.
        12.
        2017.09 구독 인증기관 무료, 개인회원 유료
        Xenotransplantation is proposed as a solution to the problem of organ shortage. However, transplantation of xenogeneic organs induces an antigen-antibody reaction in α-1,3-gal structure that are not present in humans and primates, and thus complement is also activated and organs die within minutes or hours. In this study, we used FasL gene, which is involved in the immune response of NK cell, and US11, which suppresses MHC Class I cell membrane surface expression, to inhibit cell mediated rejection in the interspecific immunity rejection, and also hDAF(CD55) was introduced to confirm the response to C3 complement. These genes were tranfeced into Korean native pig fetal fibroblasts using pCAGGS vector. And cytotoxicity of NK cell and human complement was confirmed in each cell line. The US11 inhibited the cytotoxicity of NK cell and, in addition, the simultaneous expression of US11 and Fas ligand showed excellent suppress to T-lymphocyte cytotoxicity, hDAF showed weak resistance to cytotoxicity of natural killer cell but not in CD8+ CTLs. Cytotoxicity study with human complement showed that hDAF was effective for reducing complement reaction. In this studies have demonstrated that each gene is effective in reducing immune rejection.
        4,000원
        13.
        2017.05 구독 인증기관·개인회원 무료
        Embryo development is very important in reproductive physiology of domestic animal experiments. Therefore, in the above experiment, we want to provide a lot of important information with regard to fertilization breeding by looking at the expression of transcription factor by early embryo development. It is known that mice affect early embryonic development of many transcription factors, many experiments are underway. Different types of mammals showed different expression patterns, thus, we used pigs, which are known to be the most similar to humans, to observe the expression of transcription factors in early embryonic development. Transcription factors were observed using CDX2, OCT4 and E-CADHERIN. CDX2 was expressed in 2 cells, OCT4 and E-CADHERIN were expressed in blastocyst. OCT4 was expressed specifically in ICM (inner cell mass) in blastocyst, and E-CADHERIN was expressed in cell wall and junction of blastocyst. These results show that CDX2, OCT4 and E-CADHERIN play an important role in early embryonic development in pigs.
        14.
        2017.05 구독 인증기관·개인회원 무료
        Oocyte is the central factor in the bi-directional communication axis in the ovarian follicles. It controls the cumulus or granulosa cells to perform functions which are beneficial for its own development via secreting paracrine growth factors, including GDF9 and BMP15. The aim of this study was to investigate whether the recombinant GDF9 and BMP15 are able to promote meiotic resumption and cumulus expansion of canine COCs during IVM, as well as to demonstrate the actions of GDF9 and BMP15 in regulating the expression of connexin transcripts in the ovarian granulosa cells. As results, GDF9 and BMP15 significantly improved the meiotic resumption rate and cumulus expansion by activating ERK1/2 signaling. Treatments with GDF9 significantly improved the expression of CyclinB1 but inhibited the expression of Cx43 transcripts. In addition, cumulus expansion genes (MAPK1, Ptgs2, Tnfaip6 and Ptx3) were differentially improved by GDF9 and BMP15. In the ovarian granulosa cells, GDF9 suppressed the expression of Cx43 transcripts by binding ALK4/5/7 receptors and activation Smad2/3 signaling, whereas, BMP15 stimulated the expression of Cx43 transcripts by binding ALK2/3/6 receptors and activating Smad1/5/8 signaling. In conclusion, by regulating functions of granulosa/cumulus cells, oocyte has the potential to enhance the growth and maturation of itself.
        15.
        2017.05 구독 인증기관 무료, 개인회원 유료
        Oocyte is the central factor in the bi-directional communication axis in the ovarian follicles. It controls the cumulus or granulosa cells to perform functions which are beneficial for its own development via secreting paracrine growth factors, including GDF9 and BMP15. The aim of this study was to investigate whether the recombinant GDF9 and BMP15 are able to promote meiotic resumption and cumulus expansion of canine COCs during IVM, as well as to demonstrate the actions of GDF9 and BMP15 in regulating the expression of connexin transcripts in the ovarian granulosa cells. As results, GDF9 and BMP15 significantly improved the meiotic resumption rate and cumulus expansion by activating ERK1/2 signaling. Treatments with GDF9 significantly improved the expression of CyclinB1 but inhibited the expression of Cx43 transcripts. In addition, cumulus expansion genes (MAPK1, Ptgs2, Tnfaip6 and Ptx3) were differentially improved by GDF9 and BMP15. In the ovarian granulosa cells, GDF9 suppressed the expression of Cx43 transcripts by binding ALK4/5/7 receptors and activation Smad2/3 signaling, whereas, BMP15 stimulated the expression of Cx43 transcripts by binding ALK2/3/6 receptors and activating Smad1/5/8 signaling. In conclusion, by regulating functions of granulosa/cumulus cells, oocyte has the potential to enhance the growth and maturation of itself.
        4,000원
        16.
        2016.10 구독 인증기관·개인회원 무료
        Prolonged communication between oocytes and the surrounding somatic cells is one of the unique reproductive physiology in canine. Paracrine Kit ligand (KITL) signaling is a well-known communication between granulosa cells and the oocyte. KITL is a cytokine growth factor secreted by granulosa cells that signals via the c-kit receptor expressed by oocytes. Paracrine factors, including growth differentiation factor 9 (GDF9) and bone morphogenetic protein 15 (BMP15), exert their effects by binding with the kinase receptors expressed on the granulosa cells. However, the regulations of GDF9 and BMP15 in the canine KITL expression are currently poorly understood. Therefore, we investigated the effects of GDF9 and BMP15 on the expression of KITL in canine ovarian granulosa cells in vitro. In Annexin V assay recombinant GDF9 and BMP15 did not induce apoptosis in the cultured ovarian granulosa cells. When treated, FSH significantly increased KITL expression, and hCG suppressed its expression. When both FSH and hCG were treated, the expression of KITL was affected by GDF9 and BMP15 in dose and time dependent manner in the luteal granulosa cells. GDF9 (10 ng/mL) significantly decreased KITL expression after12 h. BMP15 (10 ng/mL) significantly also decreased KITL expression after 24 h. Western blot and immunochemistry results indicate that GDF9 activated Smad2/3. After blocking ALK 4/5/7 receptors by SB, GDF9 failed to activate Smad2/3, also BMP15 did not activate Smad1/5/8 after blocking ALK 2/3/6 receptors by DM. So GDF9 exerts its effects via using ALK 4/5/7 receptors to activate SMAD2/3 signaling, and BMP15 binds ALK 2/3/6 receptors to activate SMAD1/5/8 signaling. The expression of KITL was not changed by SB or DM treatment. However, the effect of GDF9 and BMP15, which decreased the expression of KITL, was suppressed by SB or DM treatment. In conclusion, this study provides the first evidence that recombinant GDF9 and BMP15 decrease KITL expression in canine ovarian granulosa cells.
        17.
        2016.04 구독 인증기관·개인회원 무료
        Investigating loci compositions by conventional methods is limited in fully addressing complex gene information. We applied self-organizing map (SOM) to characterize Amplified Fragment Length Polymorphism (AFLP) of aquatic insects in six streams in Japan in responding to environmental variables. Locus band presence patterns were clustered by the trained SOM. Presence and absence data of loci were altered and cluster change through recognition was Subsequently expressed to indicate sensitivity to environmental variables. The outlier loci were determined based on the 90th percentile. Subsequently environmental responsiveness was obtained for each outlier in different species. Outlier loci were overall sensitive to pollutants and feeding material. Poly-loci like responsiveness was detected in adapting to environmental constraints. SOM training combined with recognition could be an efficient means of characterizing loci information without knowledge on population genetics a prior.
        18.
        2016.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study was conducted to investigate the effects of various mulching materials on growth and yield of okra (Abelmoschus esculentus L. Moench). Three kinds of polyethylene (PE) mulching materials were used which are: black (Black), green (Green), and white and black on both sides (White), black non-woven fabric (Fabric), and barley straw (Straw) and the control plot (Control) were also used in this study. The change of soil temperature was observed in various mulching materials with Green showing the highest average temperature of 24.4o, followed by Black > Fabric > Control > White > Straw. The variation of plant length,, aboveground weight, and root weight were constant in the order of Green > Black > White > Fabric > Control > Straw. Total yield (number of fruits) were 281,000 in Green which was the highest yield, and the least was from Straw which was 62.3% of Green. Total weight of fruits in Green was 395 kg which was the heaviest, and in Straw was least with 226 kg Hence, the weight of fruits
        4,000원
        19.
        2014.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The currently cultivated varieties of moth orchid flowers have weak or no fragrance and the plant requires high temperatures for cultivation. In order to develop a new variety of orchid that is psychrophilic and fragrant, intergeneric cross between wild wind orchids and moth orchids was performed. In 2009, To obtain intergeneric hybrids from Sedirea japonicum and Neofinetia falcata with moth orchids, artificial crosses with a total of 160 combinations were performed. Most of the cross combinations failed due to crossincompatibility after intergeneric crosses, with no pod formation, premature pod dropping after pod formation, and pod formation that did not produce seeds. From among these, the crosses that formed normal seeds and germinated to produce viable plants included Doritis pulcherrima × S. japonicum, N. falcata × D. pulcherrima, and N. falcata × P. equestris. From the hybrid specimens obtained through these crosses, 2 superior lines (819-3B and K9256) were selected based on their floral morphology, number of flowers, hardiness, and fragrance. Comparative analyses of the morphological and chromosomal traits were performed between the selected hybrid specimens and their parents. The flower and inflorescence characteristics of the selected hybrids exhibited intermediary traits of both the parents; however, more traits from the moth orchids were inherited. For pollinia traits, both 819-3B and K9256 specimens exhibited intermediate forms of their parents in terms of their shape and size. In the case of 819-3B specimen, a high degree of trait similarity with that of D. pulcherrima was observed; whereas, K9256 specimen showed lobes similar to that of P. equestris. The ploidy of moth orchid, S. japonicum, and N. falcata used for crosses was diploid, as determined by microscopic examination and ploidy analysis. The microscopic examination of chromosomes from the intergeneric hybrid pollens revealed mutation of the chromosome count among different specimens as well as irregular chromosome separation. For the production of next-generation progeny using the obtained hybrids, back-cross was performed; however, most of the progeny obtained were sterile and, among the 12 back-crosses, pod formation was noted in S. japonicum × 819-3B and 819-3B × S. japonicum crosses only.
        4,000원
        20.
        2014.04 구독 인증기관·개인회원 무료
        The effect of increased carbon dioxide concentration in atmosphere was examined on the pheromone system of Helicoverpa armigera reared from egg stage to adult in three room. Two of three room (2×2×2 m) were treated with carbon dioxide gas as 600 ppm and 1,000 ppm, respectively. Mean of carbon dioxide concentration was 429.1 ppm in the control, 603.3 ppm for 600 ppm, and 1011.5 ppm for 1,000 ppm during experiment. Electroantenograph (EAG) test was conducted on 3-d-old male adults with air, hexane, and a series of their sex pheromone component, Z11-16Al, from 0.01 to 100 ng. The result was that male EAG responses of 600 and 1,000 ppm were 30.3% lower than that of control room. Production of Z11-16:Al was examined on about twenty 2-d-old virgin females. Carbon dioxide increases did not show a statistically significant difference. However, higher amount of sex pheromone was produced in females of 600 and 1,000 ppm. So, This experiment was replicated with different population reared again. The amount of the sex pheromone per female was 108.9 and 118.1 ng in control room, 139.8 and 141.8 ng in 600 ppm room, and 124.6 and 125.8 ng in 1,000 ppm room.
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