• Title/Summary/Keyword: Nature of science

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Antioxidative Activity of Securinega suffruticosa Extract (광대싸리 줄기 추출물의 항산화 활성)

  • Park, Soo-Nam;Kim, Jai-Hyun;Ahn, You-Jin
    • Journal of the Korean Applied Science and Technology
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    • v.26 no.3
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    • pp.269-278
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    • 2009
  • In this study, the anti oxidative effects, inhibitory effects on elastase, and components of Securinega suffruticosa extracts were investigated. The free radical (1,1-diphenyl-2-picrylhydrazyl, DPPH) scavenging activities ($FSC_{50}$) and reactive oxygen species ROS) scavenging activities ($OSC_{50}$) of extract/fractions from Securinega suffruticosa were measured. The aglycone fraction ($9.04\;{\pm}\;0.51\;{\mu}g/mL$) and 50 % ethanol extract ($1.05\;{\pm}\;0.41\;{\mu}g/mL$) showed the most effective scavenging activities. The protective effects on the rose-bengal sensitized photohemolysis of human erythrocytes were investigated. The aglycone fraction exhibited the most prominent cellular protective effect (${\tau}_{50},\;102.77\;{\pm}\;5.37$ min at $10{\mu}g/mL$). The inhibitory effect of ethyl acetate fraction on tyrosinase were of examined ($210.0\;{\pm}\;1.02\;{\mu}g/mL$). The inhibitory effect of aglycone fraction on elastase were also investigated ($17.6\;{\pm}\;1.26\;{\mu}g/mL$). These results indicate that extract/fractions of Securinega suffruticosa can function as antioxidants in biological systems, particularly skin exposed to UV radiation by scavenging $^1O_2$ and other ROS, and protect cellular membranes against ROS. Securinega suffruticosa extract could be used as a new cosmeceutical ingredient for whitening and anti-wrinkle products.

Antioxidant Activity of Momordica charantia L. Extracts (여주 추출물의 항산화 활성)

  • Park, Yeol;Boo, Hee-Ock;Park, Young-Lan;Cho, Dong-Ha;Lee, Hyun-Hwa
    • Korean Journal of Medicinal Crop Science
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    • v.15 no.1
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    • pp.56-61
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    • 2007
  • This study was carried out to determine the antioxidant activity and vitamin C contents in plant extracts of the Momordica charantia L. The vitamin C was detected as the highest content in immature fruit (92.2 mg/100 g), while the content in stem (2.5 mg/100 g) was lower 40 times than that of immature fruit. Antioxidant activity for the dried sample was investigated by TBA method. The lowest TBARS values were obtained from extracts of dried leaf and followed by ascorbic acid and BHT, showing that the extracts from dried leaf possess the strongest antioxidant activity. Compared with fresh tissues, SOD activity, ATX activity and CAT activity were high level in the dried tissue. These results suggest that the Momordica charantia L. would be a promising antioxidant source as an alternative antioxidant, based on natural plant resources.

Comenius' Pansophism as a Historical Origin of Science Education (코메니우스의 범지주의적 교육학과 과학교육의 사상적 기원에 관한 문제)

  • Chung, Byung-Hoon
    • Journal of The Korean Association For Science Education
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    • v.14 no.3
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    • pp.379-392
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    • 1994
  • One of the historical origins of the modern science education was investigated in this paper. From the view point of the pansophistic educational philosophy which emphasized "man should teach completely all things to all mankind(Omnes, Omnia, omnino)", J.A.Comenius proposed in his book "Didactica magna"(1658) that 'physica' should be learned as one of the most important school subjects. He suggested the completion of human being as a wholeness of the universe could be achieved through the physics teaching. His ideas of science education was, however, directed not to the 'rational konwledge' about the natural world, but to the 'divine wisdom'. His main thoughts and influences on science education can be summarized as follows: 1) The human being as a God's image should know the divinely created nature, because the invisible God's existence can be sensorially recognized in the nature. 2) Physics or science should be regarded as more important objects than verbal learning in general school education. 3) The cognitive union between the words('representative' or 'das Dargestellte') and things('presentative' or 'das Dargebotene') can be achieved through the objects lesson ('Anschauungsunterricht') 4) The realistic and sensor-cognitive learning theory of the object lesson is yet very important especially in the science education of elementary school, even though the inquiry learning process has became more important in the last years. 5) The religious aspect of his idea could not satisfy the social needs of industrialization and the development of professonal technics in the 18 to 19th century.

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The Effects of Small Group Drawing in Learning the Particulate Nature of Matter (물질의 입자성에 대한 학습에서 소집단 그림 그리기의 효과)

  • Han, Jae-Young;Kim, Hun-Sik;Kim, Bo-Kyung;Noh, Tae-Hee
    • Journal of The Korean Association For Science Education
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    • v.25 no.7
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    • pp.721-727
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    • 2005
  • This study investigated the effects of small group drawing in learning the concepts of particulate nature of matter. Three classes of seventh graders (N = 126) at a coed middle school were randomly assigned to a pair drawing group, an individualistic drawing group, and a control group. The students were taught the 'three states of matter' and 'motion of molecules' for eight class periods. Prior to these classes, student self-efficacy, learning motivation, and attitude toward science instruction were examined. After instruction, tests assessing achievement, conception, learning motivation, and attitude toward science instruction were administered. Two-way ANCOVA results revealed that scores of achievement and conception for the pair drawing group were significantly higher than those for the control group. However, scores of the three groups did not significantly differ in learning motivation and attitude toward science instruction. Furthermore, no significant interactions surfaced between instruction and the level of self-efficacy in all dependent variables.

The Effects of Drawing and Analyzing Pictures in Concept Learning of the Particulate Nature of Matter: A Comparison Based on Student Visual Learning Style (물질의 입자 개념 학습에서 그림 그리기와 그림 분석하기의 효과: 시각적 학습양식에 따른 비교)

  • Han, Jae-Yeong;Lee, Ji-Young;Kwack, Jin-Ha;Noh, Tae-Hee
    • Journal of The Korean Association For Science Education
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    • v.26 no.1
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    • pp.9-15
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    • 2006
  • Students have often experienced difficulties in understanding the concept of the particulate nature of matter despite its importance in chemistry. Although various instructional methods have been suggested for teaching this concept, systematic studies have been rarely conducted. Therefore, this study investigated the effects of drawing and analyzing pictures. Three classes of 7th graders at a coed middle school in Seoul were assigned to the control group, the drawing group, and the analyzing group, respectively. Students were taught about the three states of matter and the motion of molecules for 8 class periods. The instructional effects on student conception, achievement, and science learning motivation were investigated by student visual learning styles. Results revealed that the scores of a conceptions test and a science learning motivation test for both the drawing group and the analyzing group were higher than those for the control group. Additionally, the scores of the science learning motivation test were also found to be higher for students with a more visual learning style than their counterparts.

The Influence of Hypothetical Deductive Experiment upon Students' Views on the Nature of Science (가설 연역적 탐구 실험 수업이 학생들의 과학의 본성에 대한 관점에 미치는 영향)

  • Kim, Ji-Young;Kang, Soon-Hee
    • Journal of The Korean Association For Science Education
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    • v.27 no.3
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    • pp.169-179
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    • 2007
  • We investigated the effects of hypothetical deductive experiment on students' views about the nature of science (NOS). Participants were 212 eighth graders from a middle school and they were assigned to a control group and an experimental group. Students of the control group did guided experiment in small group and students of the experimental group did hypothetical deductive experiment in small group. The results revealed that both students of the control group and the experimental group possessed similar views about NOS in a pretest. But the experimental group exhibited more sophisticated views about the theory of dependance of observation, scientific reasoning and hypothesis in the posttest. Students who used mainly surface learning strategy within the experimental group exhibited more sophisticated views about hypothesis in the posttest. On the other hand, students who used mainly deep learning strategy within the experimental group exhibited more sophisticated views about the theory of dependance of observation, scientific reasoning and hypothesis in the posttest.

Research of Suggesting Study Problems for Enhancing Self-directed Learning Ability (자기주도적 학습력 향상을 위한 학습문제 제시 방안 연구)

  • 박영희;김정길;김석중;송판섭;김해경;문병찬
    • Journal of Korean Elementary Science Education
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    • v.20 no.2
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    • pp.197-215
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    • 2001
  • The science in elementary school has the purposes of having interest and curiosity in nature phenomena and things, of understanding basic concepts of science, realizing experimental know-how for students. And it also intends students to develop self-leading research ability and creative problem-solving ability through looking-in and experience about nature. However, existing science is accepted very hard and no interesting, just bothering to prepare more then a ability-developing or interest. In this report, I will analyze the study problems suggested in science textbook from 3rd to 6th grade, then find a new way for study problem suggesting and adopt it. It would help students have interest, approach problem without tense, understand problem exactly, and stand a concreat study schedule of experiment, observation, rearrangement, result interpretation that have students study by themselves. Because the suggesting way of science study problem statement is important thing to develop students' creativity and problem- solving abillity and to make self-leading attitude, I wish the exiting, veneficial, and waiting-for science class, through apply the newly developed methology suggested in this report.

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Studies on Silk Textile Wash and Wear Finishing (絹織物 Wash and Wear 加工硏究)

  • Choe, Byong-Hee;Lee, Yang-Hoo
    • Journal of Sericultural and Entomological Science
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    • v.23 no.1
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    • pp.47-55
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    • 1981
  • Silk textile finishing has been studied for many years by many workers in order to meet more utilities for various endusers. Such studies, however, could not be successful because any natural fibers are hardly change their natures by artificial treating methods. Textile finishing is of course to improve the mechandise qualities and the poor natures of silk so that it may be available as the best textile fiber in the world. Sometimes, famous trade marked textile plays more power than its quality in the silk market, nevertheless, this should be over line of research activities. Meantime, the silk demand has been also transferred from ladies stocking to other clothes since nylon or other synthetic fibers were developed. That is why, the extension of silk demand should be developed by various research works. Specially, silk is known as difficult textile to handle it during washing or ironing process which happened to depress down the silk usage for house wives. In order to solve such problems, the reporter has been worked for many years and now, he believes that he has developed a proper finishing method to coversuch problems. The developed finishing method may be said to eligible with economical aspect and shorten the dry duration after water washing in half against normal silk textile without harming the specific silk nature. As all of us know, silk fiber starts to denature since it was spinned by silkworm and the fiber is formed as overlapped "S" type curves during its concooning process. After it is made as raw silk or sericin silk, it shows as straight line form, but it changes in to waved form in case refining or degumming process in order return to its original spinned form. Such nature is continued during its textile form and ends with hard ironing nature than other textile fibers. Mean while, the silk fiber keeps to continue its denaturing and this is iniciated by repeat of washing and drying which takes many years to reach its final stage, The reporter has found the iniciating denature of silk by his finishing process, with out heat, decreasing the swollen nature which ended with shortening the drying duration after wash. Each washing was carried out by soaking the previously weighed sample in cold water for one hour, then pressed the sample for ten minutes to eliminate its free water component before weighing with same condition. According to this, the treated silk showed much denaturing after the finishing, but the standard silk progressed the denaturing by and by with the repeat of washing and drying, finally reached the same swollen degree of treated silk, Such treating result explains that the treated silk happened to be stebilized nature by the treating immediately. On the other that the treated silk happened to be stebilized nature by the treating immediately. On the other hand, standard silk may reach to such condition by the time of worn out clothes after repeat of washing and drying for many years while the clothes will be no more useful. The decreased swelling nature has brought about the drying period in half against standard silk after all. Not only the tests of tenacity and elongation but also crease resistance recovery, stiffness and shrinkage tests were carried out after each washing and drying which he has found better result on the treated silk textile against the standard silk. The most important thing was to keep the textile feeling of silk by such finishing work before improve any poor nature of silk. The general silk has a nature to absorb smoke or dirt from its surrounding air and reaches to dirty color shade upon such exposure, but the treated one has improved such nature because of its artificial denaturing, another word, it keeps clean longer than the normal silk. Many previous finishing works could improve some specific nature of silk, but it happened to deprave other important natures. The reporters work is, however, specialized to improve the silk to be useful as Wash and Wear Silk without harming its standard natures. So far, this work happened to be a overall innovative finishing method of silk textile.

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Requirements to Accept the Medical-service Person's Professional Negligence in the Medical Malpractice Case Occurred being on Duty - With its focus on the Precedent case no. 2005Do314, Sentenced by June 10, 2005, by The Supreme Court - (당직 근무 중 발생한 의료사고에서 당직의료인의 업무상과실을 인정하기 위한 요건 - 대법원 2005.6.10. 선고 2005도314 판결을 중심으로 -)

  • Kim, Young-Tae
    • The Korean Society of Law and Medicine
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    • v.9 no.1
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    • pp.285-317
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    • 2008
  • To accept the doctor's professional negligence in the medical malpractice, the mistakes, by which the doctor did not foresee the production of the results in spite of the possibility of foresight and did not avoid the production of the results in spite of the possibility of avoidance, must be considered, and to decide the presence of the doctor's professional negligence, the standard must be the attention standard of general-common doctor engaged in the same business and the same function, and the medical enviornments, the conditions, the extraordinary nature of medical behavior, and etc should be considered by the general level of medical science at the time of accident. This principlel must be applied to the medical malpractice case occurred being on duty without exception. But, because of the extraordinary nature of duty work, it is difficult for any doctor to do one's best technical practice by making all diagnosis, medical treatment with all the equipment on the same plane as the ordinary times. That cannot be also expected for any doctor to do one's best technical practice in the terms of a social idea. From this point of view looking into The Precedent case related to Medical-service person being on duty sentenced by The Supreme Court, unlike the general medical malpractice case, the presence of the professional negligence in the medical malpractice occurred being on duty seems to be decided with more consideration on the general level of medical science, the medical enviornments and the conditions, particularities of medical practice at the time of accident. Especially, the extraordinary nature of medical behavior of the medical service person being on duty in the emergency room seems to be admitted compared to that of the medical service person being on duty in ward.

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