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        검색결과 146

        2.
        2024.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The secondary growth model for Salmonella was developed based on the artificial neural network (ANN) with data collected from ComBase and FoodData Central. In addition to the existing secondary model variables (temperature, pH, Na+, and water contents), more input variables (sugar, carbohydrate, lipid, and protein contents) were considered. The output variables were microbial growth parameters (lag phase duration [l] and maximum growth rate [mmax]). A commercial ANN program (NeuralWorks Predict) was utilized with training at 80%, validation at 10%, and test data at 10%. ANN models were created using all data and cleansed data. Using the cleansed data, the training/testing root mean square error (RMSE) for mmax improved from 0.14/0.16 to 0.11/0.14, whereas the RMSE for l was still not acceptable, from 11.94/33.03 to 7.09/4.18. The l data were divided into two ranges with high and low goodness of fit, whereas the ANN model for each field was built, resulting in an optimally low RMSE.
        4,000원
        3.
        2023.10 구독 인증기관·개인회원 무료
        The cherry tree borer, Synanthedon bicingulata (Staudinger, 1887), is considered as a tree boring pest boring into cambium layer and weakens the tree. Cherry trees, the host species of S. bicingulata, are the most abundant ornamental trees in South Korea. However, there has been insufficient study conducted on ornamental trees compared to orchards. The study aimed to investigate the injury patterns caused by their larvae based on height and direction they faced. Since life cycle of S. bicingulata in Gangwon province had not been surveyed, occurrence pattern was also investigated using sex attractant. Injury patterns of 253 cherry trees in Chuncheon, were surveyed in April 2023. As a result, the injury occuring under 1 m in height was 2.61 times more extensive than injury between 1m and 2m in height of trunk. Also, the injury on the south-faced trunks was 2.68 times larger than on the north-faced trunks.
        4.
        2023.10 구독 인증기관·개인회원 무료
        Honey bees are crucial pollinators for agricultural and natural ecosystems, but are experiencing heavy mortality in Korea due to a complex suite of factors. Extreme winter losses of honey bee colonies are a major threat to beekeeping but the combinations of factors underlying colony loss remain debatable. Finding solutions involves knowing the factors associated with high loss rates. To investigate whether loss rates are related to Varroa control and climate condition, we surveyed beekeepers in korea after wintering (2021–2022 to 2022–2023). The results show an average colony loss rate of 46%(2022) and 17%(2023), but over 40% colony loss before wintering at 2022. Beekeepers attempt to manage their honey bee colonies in ways that optimize colony health. Disentangling the impact of management from other variables affecting colony health is complicated by the diversity of practices used and difficulties handling typically complex and incomplete observational datasets. We propose a method to 1) Varroa mite population Control by several methods , and 2) Many nursing bee put in hive before wintering.
        5.
        2023.05 구독 인증기관·개인회원 무료
        CANDU Spent Fuel (CSF) dry storage system, SILO, has been operated from 1992 at Wolsung under 50 year operating license. As of 2023, this system has been operated for over 30 years and its licensed remaining operation time is less than 20 years. When it faces the final stage of operation, it has only two options; moving to a centralized away-from-reactor storage or extending its license atreactor. These two options have an inevitable common duty of confirming the CSF integrity by a “demonstration test”. Since the degradation of CSF and structural materials in the SILO are critically dependent on temperature, two important goals of the ‘DEMO test’ were set as follows. 1. Design of ‘DEMO SILO’: Development of internal monitoring technology by transforming SILO design. 2. Accurate measurement and evaluation of the three-dimensional temperature distribution in the ‘DEMO SILO’ Based on operating real commercial SILO dimension, a conceptual “DEMO SILO” design has been developed from 2022. Because, unlike with commercial Silo, ‘Demo Silo’ must be disassembled and assembled, and have penetration holes. Safety evaluation technologies like structural, thermal and radiation protection analysis also have been developed with design work. ‘Demo SILO’ should evaluate an accurate 3D temperature distribution with minimal number of thermocouples and penetration holes to avoid disruption of internal flow and temperature distribution. For this reason, a ‘Best Estimate Thermal-Hydraulics evaluation system for SILO’ is under development and it will be essential for ensuring temperature prediction accuracy. Construction of a full-scale test apparatus to validate this technology will begin in 2024. In order to supply power to many heaters and monitor temperature gradient inside of this apparatus, it has modular design concept by dividing its whole body to axial 9 sub-bodies which looks like a donut containing a basket at center position.
        8.
        2022.09 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Lactic acid bacteria as probiotics are intensively used in human and animal species. These probiotic properties of LABs were variable according to bacterial strain and species. However, there was limited information on probiotic properties of monkey origin LABs. In this study, we investigated the antibacterial activity of monkey and human origin LABs against monkey origin enteric bacteria by the agar disc diffusion test and broth culture inhibition assay. All LABs represented enough tolerance to pepsin (0.3%) and bile acid (pH = 2). To 50% of Clostridium perfringens and 20% of Escherichia coli, monkey origin LABs showed statistically higher antibacterial activity compared to human origin LABs (p < 0.05). Also, distinct antibacterial activity was verified among some bacteria species and strains. Higher antibacterial activity against enteric bacteria except for C. perfringens was verified in Lactobacillus johnsonii strains compared to Lactobacillus reuteri and Lactobacillus salivarius. Statistically different antibacterial activity against C. perfringens was verified among strains within L. reuteri and L. johnsonii. In conclusion, we prove the higher probiotic properties of monkey origin LABs against homogenous enteric bacteria although humans and monkeys were phylogenetically similar species. For non-human primates, homogenous LABs should be used as probiotics, not human origin LABs. Furthermore, it was confirmed among monkey origin LABs, L. johnsonii showed a high antibacterial activity on various enteric pathogenic bacteria and was an appropriate lactic acid strain for inhibiting C. perfringens.
        4,200원
        20.
        2019.06 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Acute myocardial infarction (AMI) is considered the major cause of mortality in the world. Tremendous animal studies are performed to develop novel therapeutics, and this study aimed to induce porcine myocardial infarction model by using polyethylene terephthalate (PET). Coronary guidewire was placed in left anterior descending artery (LAD). The balloon angioplasty catheter was inserted at the back of the PET. The balloon catheter was carefully pushed forward, until the balloon marker was located in mid-LAD. Coronary angiography was performed pre- and post-occlusion at 28 days by C-arm. Histologic analysis of heart tissue was performed 28 days after inducing AMI. Thirty three pigs were anesthetized and underwent percutaneous coronary catheterization. All pigs were successfully embolized in mid-LAD by PET. Fifteen pigs died due to ventricular fibrillation during post-anesthetic recovery time, and overall experiment mortality was 45.5%. In 2,3,5- triphenyl tetrazolium chloride staining, gross finding of the ischemic heart lesion showed firm and white area of infarction associated with the apex and left ventricular posterior wall. Infarct on H&E-stained sections demonstrated a region without myocytes and rich with cardiomyocyte with atypical nuclei. Successful induction of AMI by using PET may provide the pathophysiological information of ischemic heart disease and improvement of therapy development for AMI.
        4,000원
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