• Title/Summary/Keyword: Combinatorial Chemistry

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A Status Survey and Improvement Plan for the Science Education in Vocational High Schools (실업계 고등학교 과학교육의 실태분석과 개선방안)

  • Pak, Sung-Jae;Kwon, Jae-Sool;Kim, Chang-Sik;Oh, Dae-Sub;Woo, Jong-Ok;Lee, Wha-Kuk;Cho, Hee-Hyung
    • Journal of The Korean Association For Science Education
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    • v.8 no.1
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    • pp.1-22
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    • 1988
  • The educational policy of a nation should be based on the results of nation-wide studies and their analyses. This study is the third one in a series of research on "development of improvement plan and monitoring system for secondary school science", focusing on the three major areas, such as students' achievements, science instruction and conditions for science education in vocational high schools. In general, the results showed that science achievements in vocational high schools were significantly lower than those of general high schools. While the achievement level in physics was lower by one percent, the achievement levels in chemistry and biology were significantly lower by more than 5 percents. In the case of scientific inquiry, the results showed much lower scores compared to those of general high schools. Concerning the inquiry abilities, most of the students did not possess the formal operational thinking skills such as controlling variables and combinatorial thinking. The ability of experimental skills seemed to be closely related to the students' majors. Students in industrial arts schools could measure electric resistance very well, while students in agricultural high school students failed completely. In the area of students' attitude toward science, the greater part of the students had the experiences of using scientific equipments (68.6 %), experimentation (54.3 %), and extracurricular science activities (56.9 %). They also showed positive attitude towards the nature of science (59.8%). The results of the survey on science instruction and school conditions for science education showed the needs for improvement In general, the priority of science education in vocational high schools was very low compared to their major subjects. The teachers as well as students thought science text books nor to be difficult These responses and the low achievement levels seemed to be contradictory to each other. The facilities for science experiments were better equipped and installed to general high schools. However. the lack of budget was a major problem for performing experiments uning the facilities. Therefore. science education in vocational high school have many things to be improved For the improvement of science education in vocational high schools, financial support as well as the intention for the improvement must be the essential factors.

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A prognosis discovering lethal-related genes in plants for target identification and inhibitor design (식물 치사관련 유전자를 이용하는 신규 제초제 작용점 탐색 및 조절물질 개발동향)

  • Hwang, I.T.;Lee, D.H.;Choi, J.S.;Kim, T.J.;Kim, B.T.;Park, Y.S.;Cho, K.Y.
    • The Korean Journal of Pesticide Science
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    • v.5 no.3
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    • pp.1-11
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    • 2001
  • New technologies will have a large impact on the discovery of new herbicide site of action. Genomics, combinatorial chemistry, and bioinformatics help take advantage of serendipity through tile sequencing of huge numbers of genes or the synthesis of large numbers of chemical compounds. There are approximately $10^{30}\;to\;10^{50}$ possible molecules in molecular space of which only a fraction have been synthesized. Combining this potential with having access to 50,000 plant genes in the future elevates tile probability of discovering flew herbicidal site of actions. If 0.1, 1.0 or 10% of total genes in a typical plant are valid for herbicide target, a plant with 50,000 genes would provide about 50, 500, and 5,000 targets, respectively. However, only 11 herbicide targets have been identified and commercialized. The successful design of novel herbicides depends on careful consideration of a number of factors including target enzyme selections and validations, inhibitor designs, and the metabolic fates. Biochemical information can be used to identify enzymes which produce lethal phenotypes. The identification of a lethal target site is an important step to this approach. An examination of the characteristics of known targets provides of crucial insight as to the definition of a lethal target. Recently, antisense RNA suppression of an enzyme translation has been used to determine the genes required for toxicity and offers a strategy for identifying lethal target sites. After the identification of a lethal target, detailed knowledge such as the enzyme kinetics and the protein structure may be used to design potent inhibitors. Various types of inhibitors may be designed for a given enzyme. Strategies for the selection of new enzyme targets giving the desired physiological response upon partial inhibition include identification of chemical leads, lethal mutants and the use of antisense technology. Enzyme inhibitors having agrochemical utility can be categorized into six major groups: ground-state analogues, group specific reagents, affinity labels, suicide substrates, reaction intermediate analogues, and extraneous site inhibitors. In this review, examples of each category, and their advantages and disadvantages, will be discussed. The target identification and construction of a potent inhibitor, in itself, may not lead to develop an effective herbicide. The desired in vivo activity, uptake and translocation, and metabolism of the inhibitor should be studied in detail to assess the full potential of the target. Strategies for delivery of the compound to the target enzyme and avoidance of premature detoxification may include a proherbicidal approach, especially when inhibitors are highly charged or when selective detoxification or activation can be exploited. Utilization of differences in detoxification or activation between weeds and crops may lead to enhance selectivity. Without a full appreciation of each of these facets of herbicide design, the chances for success with the target or enzyme-driven approach are reduced.

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