• Title/Summary/Keyword: school laboratory

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Analysis of Elementary School Teachers' Laboratory Instruction Process through Experiments from Science Laboratory and Engineering Laboratory (과학적 실험과 공학적 실험에서 초등교사의 수업 과정 분석)

  • Lim, Jae-Keun;Lee, So-Ree;Yang, Il-Ho
    • Journal of Korean Elementary Science Education
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    • v.29 no.4
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    • pp.515-525
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    • 2010

  • The purpose of this study was to analyze of how the elementary school teachers lead their classes of a science laboratory instruction and an engineering laboratory instruction in a science subject class. For this study, science laboratory and engineering laboratory lessons were selected and for each science and engineering laboratory lesson, five elementary school teachers were video-recorded of their lessons. The science and engineering laboratory lessons were analyzed by utilizing processes of the science model and the engineering model based on Schauble et al. (1991). The results of these studies are as follows: In science laboratory instruction, some participants didn't distinguish the difference between the science laboratory goal and the engineering laboratory goal. All of participants used search and end strategy of engineering laboratory for science laboratory lesson. In engineering laboratory instruction, all of participants guided to students engineering laboratory goal and used inferences and search strategy of engineering laboratory. However they didn't use the trial and error strategy or redesign which can be an essential element in engineering and design process. Educational implications are discussed.

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Nattokinase Crude Extract Inhibits Hepatocellular Carcinoma Growth in Mice

  • Yan, Yongmin;Wang, Yanjing;Qian, Jiali;Wu, Sihui;Ji, Yi;Liu, Yanxiao;Zeng, Jian;Gong, Aihua
    • Journal of Microbiology and Biotechnology
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    • v.29 no.8
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    • pp.1281-1287
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    • 2019

  • Nattokinase (NK, E.C. 3.4.21.62) is a serine protease produced by Bacillus subtilis natto that shows promise for the treatment of thrombotic disease. In this study, we assessed the effects of NK on the development of hepatocellular carcinoma (HCC), a principal malignancy of the liver that causes morbidity and mortality worldwide. Crude extracts of NK (NCE) were isolated from fermentation medium by centrifugation and separated into three fractions (<10 K, 100~30 K and >30K). Orthotopic HCC mouse models were established and NCE was administered by oral gavage. H&E staining was performed to examine the pathology of HCC livers. Immunohistochemistry and immunofluorescence were used to evaluate FOXM1, CD31, CD44 and vimentin expression in the liver. Compared to PBS groups, NCE increased the survival rates of HCC-bearing mice to 31% and decreased ascites. Low-intensity ultrasound imaging showed that the hypoechoic mass area was lower in NCE-treated mice and that tumor growth significantly decreased. IHC staining showed that the expression of FOXM1 was inhibited by NCE treatment. Immunofluorescence results revealed lower levels of CD31, CD44 and vimentin in the NCE groups. Taken together, these data demonstrate that NCE from Bacillus subtilis natto improves survival and inhibits tumor growth in HCC mice.

  • https://doi.org/10.4014/jmb.1812.12058 인용 PDF KSCI