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        검색결과 13

        1.
        2023.11 구독 인증기관·개인회원 무료
        After the major radioactivation structures (RPV, Core, SG, etc.) due to neutron irradiation from the nuclear fuel in the reactor are permanently shut down, numerous nuclides that emit alpha-rays, beta-rays, gamma-rays, etc. exist within the radioactive structures. In this study, nuclides were selected to evaluate the source term for worker exposure management (external exposure) at the time of decommissioning. The selection of nuclides was derived by sequentially considering the four steps. In the first stage, the classification of isotopes of major nuclides generated from the radiation of fission products, neutron-radiated products, coolant-induced corrosion products, and other impurities was considered as a step to select evaluation nuclides in major primary system structures. As a second step, in order to select the major radionuclides to be considered at the time of decommissioning, it is necessary to select the nuclides considering their half-life. Considering this, nuclides that were less than 5 years after permanent suspension were excluded. As a third step, since the purpose of reducing worker exposure during decommissioning is significant, nuclides that emit gamma rays when decaying were selected. As a final step, it is a material made by radiation from the fuel rod of the reactor and is often a fission product found in the event of a Severe accident at a nuclear power plant, and is excluded from the nuclide for evaluation at the time of decommissioning is excluded. The final selected Co-60 is a nuclide that emits high-energy gamma rays and was classified as a major nuclide that affects the reduction of radiation exposure to decommissioning workers. In the future, based on the nuclide selection results derived from this study, we plan to study the evaluation of worker radiation exposure from crud to decommissioning workers by deriving evaluation results of crud and radioactive source terms within the reactor core.
        4.
        2017.07 구독 인증기관·개인회원 무료
        With the development of information technology, the market situation is changing more rapidly than ever. The change is most rapid in the preferences and lifestyle of consumers. For companies to survive in such an environment, it is indispensable to develop innovative and competitive new products by better understanding the needs of consumers. Any novel and meaningful idea of a new product basically originates from knowledge, which plays an important role in the performance of new products because it is the most valuable asset for a business entity. In this study, the author considers the knowledge sharing process as a dynamic aspect based on the term “knowledge,” carrying a static meaning as used in the existing research. The nature of the knowledge sharing process pertaining to new product development has been largely divided into three terms and then re-established. The author focuses on a new product development team as the subject of sharing and providing knowledge on new products, and regards the solution to problems that may arise in the development process as the stability of the team. The moderating effect was examined by the relationship between the type of knowledge sharing process and the outcome of the new product with the variable of team stability. The results indicate that the convergence and similarity of the knowledge sharing process affect new product performance as positive variables, whereas the tacitness of the knowledge sharing process does not lead to a significant result in terms of performance of new products. This study also shows that the stability of the team has a positively direct effect on the outcome of the new product. Thus, the convergence process of various kinds of knowledge positively affects the diversity and innovation of new product concepts. Moreover, the same recognition area or shared goal awareness and sense of responsibility play important roles in the performance of the new product. The moderating effect of team stability between the type of knowledge sharing process and new product performance is described in the convergence and tacitness of the knowledge sharing process. In the process of merging existing knowledge with new knowledge or sharing embedded knowledge in the members with, the activity wherein the members of the NPD team communicate and collaborate with each other over a long period of time will provide opportunity to improve the performance of the new product. The purpose of this paper is to examine the relationship between the type of knowledge sharing process, the stability of the team, and new product performance. Academic and managerial implications and the directions for future research are discussed as well.
        5.
        2013.03 구독 인증기관 무료, 개인회원 유료
        Artificial insemination (AI) has been performed widely in swine industry using fresh liquid sperm instead of frozen type of sperm. However fresh sperm are not able to preserve more than three days with optimal motility and other sperm parameters for the successful fertilization, since in vitro stored sperm has an oxidative stress that resulted increase of abnormality and acrosome reation. To overcome these major problems, novel preservative formulation is needed to neutralize the oxidative stress and to provide suitable physiological environment for sperm in in vitro. In this study, naturally derived substances such as Poncirus trifoliate (Trifoliate orange), Garcinia mangostana (Mangosteen), pig placenta and testis extracts were tested as sperm preservative agents. Placenta extracts (PE), trifoliate orange extracts (TOE), testes extracts (TE) and mangosteen extracts (ME) were applied to analyze specific parameters for sperm motion characteristics individually and combinatorial. Each individual extract treatment can accelerate the sperm motility but noticeably TOE, TE and ME treatments exhibited the considerable and significant preservation of sperm motility. PE, TE and ME showed a significant (p<0.05) increase in ALH after one week. Further we evaluated the five different combinations of these extracts on sperm motility and its motion characteristics. Surprisingly even after one week ME, TOE and TE combination significantly preserved the sperm motility about 75%. It is noteworthy that unlike individual extract treatment, combination of ME, TOE and TE simultaneously protect the sperm motility and its motion characteristics. Taken together these data conclude that addition of ME, TOE and TE can be effective for preservation of pig sperm.
        4,000원
        6.
        2012.06 구독 인증기관·개인회원 무료
        Althogh Spermatogonial stem cells (SSCs) are widely studied in mice, study of pig SSCs is not sufficient for the isolation, long-term culture, and characterization. To identify the effect of growth factor in cultured pig SSC, newly generated pSSCs like cell from neonatal 5days porcine testis were cultured and investigated for the pSSCs like cell formation. Glial derived neurotrophic gactor (GDNF), fibroblast growth factor (FGF), leukemia inhibitory factor (LIF), and epidermal growth factor (EGF) were applied to culture media to identify the pSSC like cell growth and stem cell formation. The criteria for the determining of stem cell characters, morphology, number of colonies, putative stem cell marker were analysed by microspic, polymerase chain reaction (PCR) and immunocytochemistry (ICC) methods. Most of the pSSCs like cells were formed approximately 100 μm size with sphere shape. Most of the feeder cells were highly dependent on FGF that feeder cells were not stably attached on plate without FGF and colony formation of pSSC was not observed consequently. Immunocyto chemistry data revealed that this cells expressed the ubiquitin-C-terminal hydrolase 1 (UCHL-1, PGP9.5) and Dolichos Biflorus Agglutinin (DBA) in addition of 20 ng/ml EGF, 10 ng/ml FGF, 10 ng/ml GDNF, 10 U3/ml LIF. In addition, Alkaline Phosphatase ()was positive in all period of culture. This study suggest that various growth factorsinp SSC culture system is important to regulate and maintain the pSSC. In conculsion, although the precise role of growth factor in pSSC proliferation need to be clarified, combination of growth factor might be critical in order to derivation and proliferation of neonatal pSSCs and spermatogenesis.
        7.
        2012.06 구독 인증기관·개인회원 무료
        INTRODUCTION In rodent, molecular markers of spermatogonia, spermatocyte, spermatid and sperm have been identified. It has been reported that DBA, PGP 9.5 and NanpG can be the markers for spermatogonia in pig. For further understanding the spermatogenesis of the pig on morphological and molecular level, we report identification of testicular cells in neonatal and pubertal pig testis, and a putative marker for spermatogonia and spermatid in pig testis. MATERIALS AND METHODS Neonatal (3 day) and pubertal testis (150 day) was cut and fixed in Bouin’s solution for immunohistochemistry (IHC). Gonocytes were isolated from neonatal testis for immunocytochemistry (ICC). Based on references (Phillips et al., 2010), thirteen antibodies (VASA, Oct4, NanoG, PGP 9.5, DAZL, SCF, GFR-alpha 1, PLZF, c-kit, integrin-beta1, Thy1, Sohlh1 and CD9) were used for IHC and ICC. Paraffin section was performed for IHC. Gonocytes were attached to the APS-coated slides for ICC. HRP-conjugated and florescent-labeled secondary antibody was used for IHC and ICC, respectively. RESULTS In histological analysis, spermatogonia and Sertoli cells, which are enclosed by seminiferous tubule and connective tissue, were observed in neonatal testis. However, complete spermiogenesis, including spermatocyte, spermatid and spermatozoa, was not observed in neonatal testis. Spermatocyte, spermatid and elongated spermatid were observed in pubertal testis but matured spermatozoa were not observed. As a result, two antibodies (PGP 9.5 and GFR-alpha1) of thirteen antibodies were available for IHC and ICC. As reported in other studies, PGP 9.5 protein was detected in spermatogonia of ne-onatal in IHC. In addition, it was observed in spermatogonia of pubertal testis. GFR- alpha1 protein was detected in spermatogonia of neonatal testis and spermatid of pubertal testis. In ICC, PGP 9.5 protein was detected in gonocytes as reported in other studies. GFR-alpha1 was also observed in gonocyte isolated from pig testis. In this study, we found that 1) only spermatogonia exist in neonatal pig testis (3 day), 2) GFR-alpha1 is a new marker for spermatogenesis in pig testis.
        8.
        2012.06 구독 인증기관·개인회원 무료
        Interferon induced transmembrane protein-1 (IFITM1) is one of transmembrane protein which is differentially expressed in uterus during estrus cycle and pregnancy, that IFITM1 gene is highly expressed in estrus stage by the effect of estrogen, and in parturition by the effect of PGF2 alpha. This genes are also up-regulated in cells with hyperactivation of the WNT/β-catenin signaling pathway. In this study, to identify a function of IFITM1, the binding partner of IFITM1 were determined using immunoprecipitation and LC- MASSMASS methods. 1, 3 and 5 ug of polyclonal anti-IFITM1 antisera were used for immunoprecipitation, and the 75 kDa of specific band was detected in silver stained polyacylamide gel. This band were chracterized using LC-MASS-MASS, and revealed this band is glucose regulated protein 75 (GRP75) which binds to p53 and inhibits the p53 action in nucleus. To identify the localization of GRP75 in cells, immunocytochemical approach has been applied, and GRP75 is expressed in mitochondria of L929 murine connective tissue cells. Co-localization study between IFITM1 and GRP75 in L929 cell identified that these two proteins were closely expressed in mitochondria. Although the role of the interaction of these two protein need to be clarified in various biological phenomena, this data suggest that close interaction of IFITM1 and GRP75 may regulate cellular functions in uterus on sets of estrus cycle and pregnancy.
        9.
        2018.04 서비스 종료(열람 제한)
        Extravasation is the accidental injection or leakage of fluid into the subcutaneous or perivascular tissues. Some drugs can cause serious injury such as severe tissue injury, necrosis, and etc. Here we report a case of chemical burn by sodium bicarbonate extravasation due to accidental venous puncture during arterial cannulation. A 42-years-old woman has taken emergency laparotomy surgery due to a stab wound to the abdomen. Massive blood loss has developed, and consequently vital signs were unstable and metabolic acidosis has developed. Sodium bicarbonate has administered via a peripheral intravenous line on the dorsal vein of a right hand that runs to the cephalic vein. However, the cephalic vein that runs by the side of the radial artery has punctured accidentally during the attempt of right radial artery cannulation. Second degree superficial and deep chemical burn by sodium bicarbonate extravasation has developed. Skin lesion about 3 × 4 cm2 with erythema and bullae formation has developed. There were no necrotic changes and the digital sensation was intact. Wet dressing and silicon foam dressing were prescribed. After two weeks, she was discharged. Until then, dermis exposure about 1 × 1 cm2 remained although the skin lesions became getting well.
        11.
        2003.06 KCI 등재 서비스 종료(열람 제한)
        Kwanganbyeo is a japonica rice variety developed from the cross between Namyang 7 and SR14779-HB234-31, anelite line derived from the cross between Cheonmabyeo and Aichi 37 at the National Crop Experiment Station, RDA, and washi-tecture and light-dark gre
        13.
        2000.03 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to assess the allelopathic potentiality of Korea traditional seventy-nine rice (Oryza sativa L.) cultivars on barnyardgrass (Echinochloa crus-galli P. Beauv. var. oryzicola Ohwi) and to identify possible allelopathic compounds from selected rice cultivars, such as Seogandodobyeo, Huadobyeo and Heugbalbyeo. In the straw mixture, Seogandodobyeo showed the greatest inhibition (67.07%) on total emergence percentage. The greatest inhibition on total seedling length and dry weight of barnyardgrass occurred in Huadobyeo (58.32 %) and Heugbalbyeo (81.20%), respectively. An HPLC analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compound depend upon the cultivars. Four compounds including Ο-coumaric acid in Seogandodobyeo extracts, four compounds including p-coumaric acid in Huadobyeo extracts, and seven compounds including Ο-coumaric acid in Heugbalbyeo were detected, respectively. Ο-coumaric acid (0.97 mg/g) in Seogandodobyeo, p-coumaric acid (0.92mg/g) in Huadobyeo and Ο-coumaric acid (1.02 mg/g) in Heugbalbyeo was detected as the highest amounts, respectively. The preliminary identification by HPLC analysis resulted in peaks with retention times close to those of standards which were confirmed with EI/MS. The mass spectra of p-coumaric, and Ο-coumaric acids showed molecular ions (m/z) at 164 and 164, and their base peaks (m/z) at 164 and 118, respectively.