• Title/Summary/Keyword: aims of laboratory activity

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An Analysis of Laboratory Instructions in Elementary School Science (초등학교 과학 실험 수업 분석)

  • Yang, Il-Ho;Jeong, Jin-Woo;Hur, Myung;Kim, Young-Shin;Kim, Jin-Soo;Cho, Hyun-Jun;Oh, Chang-Ho
    • Journal of Korean Elementary Science Education
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    • v.25 no.3
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    • pp.281-295
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    • 2006
  • The purpose of this study was to analyze laboratory instructions used in elementary school science lessons by utilizing an analysis instrument for science laboratory instruction(AISLI). This analysis instrument was comprised of 3 elements; the aim of the laboratory activity, the interaction generated, and the inquiry process. There were also a total of 20 sub-categories and its validity was identified at 0.89 by four science educators. For the purposes of this study, 90 laboratory instructions were video-recorded, then transcribed. Laboratory instructions were analyzed by three analyst teams, and the inter-rater reliability within teams was checked through Pearson correlation, with a score of 0.91. The results of this study were as follows: the two principle aims of laboratory activity, namely, to acquire declarative knowledge and to increase attitudes toward science, were observed to be in evidence in 98.9% and 92.2% in laboratory instructions, and the levels of categories of the interaction and inquiry processes were situated at level-1. The implications of these results are that laboratory instructions currently in use do not place sufficient demands upon students' scientific thinking and are not at all conducive to student-centered activities. Therefore in order to remedy this situation, the usefulness of current science laboratory instructions need to be re-evaluated.

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Analyses of the Aims of Laboratory Activity, Interaction, and Inquiry Process within Laboratory Instruction in Secondary School Science (중등학교 과학 실험 수업에 대한 실험 목적.상호 작용.탐구 과정의 분석)

  • Yang, Il-Ho;Jeong, Jin-Woo;Kim, Young-Shin;Kim, Min-Kyung;Cho, Hyun-Jun
    • Journal of the Korean earth science society
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    • v.27 no.5
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    • pp.509-520
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    • 2006
  • The purpose of this study was to analyze laboratory instructions in a secondary school science with an analysis instrument on science laboratory instruction. For its purpose, we used an instrument that analyzes three dimensions of the secondary laboratory instructions. This analysis instrument was composed of 3 categories (the aim of the laboratory activity, interaction, and inquiry process) which are spread into 20 sub-categories, and its validity was checked by four science educators with factor of 0.89. For its purpose, 21 sessions of lab instructions were video-recorded and transcribed. According to the results, in the aims category, the instructions mainly focused on two aims; acquiring the declarative knowledge and increasing attitudes toward science. In the interaction category, some of the observations made were that the teachers's questions could not gather the students' divergent thinking, their directive instructions were centered around themselves rather than giving opportunities for students to be centered within laboratory activities, and students' interaction were rarely shown. Therefore, interaction was classified as level I. In the inquiry process, presenting phenomenon or questionings about the subjects were little observed, and students' hypothesizing and predicting were almost nonexistent. Most of the activity designs within lab session were given from the teachers' directions or worksheets, and students solely focused on data collecting and recording. Hence, inquiry process were classified level I.

Comparison between Secondary School Science Teachers' and Students' Perceptions about the Important Aims of Laboratory Activities in Science Instructions (중·고등학교 과학실험활동의 목적에 대한 교사와 학생의 인식 비교)

  • Cho, Hyunjun;Yang, Il-Ho;Lee, Hyonyong
    • Journal of Science Education
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    • v.32 no.2
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    • pp.103-120
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    • 2008
  • The purpose of this study was to compare science teachers' perceptions with students' perceptions about the important aims of laboratory activities in science instructions, to identify whether there was a difference between them. For the purpose, the two questionnaires were designed; for secondary science teacher and secondary student. The samples selected in each group were 108 middle school teachers, 109 middle school students, 104 high school teachers, and 110 high school students. The survey responses from each group were analyzed through multiple response method. The results indicated that science teachers selected the science process skills as important aim of laboratory activity whereas students selected the ability for creative problem-solving and the central tendency of teachers' responses about certain item-science process skill was relatively higher than students' responses about certain item-the ability for creative problem-solving. From these results, we found there was the difference between teachers' perception and students perception about the important aims of laboratory activities in science instructions.

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Optimization of Processing Conditions of Chinese Smoke-cured Bacon (Larou) with a New Natural Coating Solution during Storage Period

  • Liu, Na;Zhu, Qiujin;Zeng, Xuefeng;Yang, Bowen;Liang, Meilian;Deng, Li;He, Laping;Liang, Cai;Zhang, Ruping;Zhou, Juan
    • Food Science of Animal Resources
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    • v.38 no.3
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    • pp.636-652
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    • 2018
  • The study aims to determine the optimum sterilization rate and water activity of Chinese traditional smoke-cured bacon product (Larou) in the preservation with natural coating solution. With the response surface methodology (RSM), we analyzed 3 factors of processing conditions (the concentration of lysozyme, concentration of sodium alginate, and concentration of chitosan) and 2 response factors (sterilization rate and water activity). Sterilization rate and water activity of Larou were largely affected by the concentration of lysozyme, concentration of sodium alginate, and concentration of chitosan. The final optimum concentrations of lysozyme, sodium alginate, and chitosan were 0.09, 1.40, and 1.60% and realized the high sterilization rate. Water activity of sliced Larou was significantly correlated with the sterilization rate. Low-field nuclear magnetic resonance analysis verified the optimum processing conditions. The coating resulted in 99.69% rate of reducing bacteria after 30-day storage. The data of the total number of colony, peroxidation value, moisture content, pH, and sensory evaluation provided the theoretical basis for extending the shelf life of Chinese traditional smoke-cured bacon product (Larou) with natural coating solution.

A Study on Actual Conditions of Muscular Strength in Korean Electronics Industry (한국전자산업에서의 근력 실태에 관한 연구)

  • Park, Jung-Sik
    • Journal of the Korea Safety Management & Science
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    • v.11 no.3
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    • pp.27-32
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    • 2009
  • Human physical activity to lead daily life is performed by a variety of muscular activity strategies. These strategies can be influenced by characteristics, difficulty and muscle fatigue of work. Therefore this study examines muscular strengths (grip and back strength) of workers engaged in electronics industry in Korea, compares them to mean value of muscular strength by sex and age, accumulates related data and then aims to develop improvement methods of working environment and prevention/management program.

Inhibition of 5α-reductase of de novo Generation of Short Anti-oxidant Peptides

  • Lee, Sung-Gyu;Kang, Hyun
    • Biomedical Science Letters
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    • v.24 no.3
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    • pp.263-269
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    • 2018
  • This study aims to investigate the biological activities related to hair loss of short anti-oxidant peptides (DK peptides) $5{\alpha}$-reductase inhibition and anti-oxidation. The series of DK peptides were generated amphipathic helical properties using leucines, lysines and tryptophan residues. Cell viability and free radical scavenging activities were performed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl-tetrazolium bromide (MTT) and 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assay, respectively. The DK peptides were investigated for inhibitory activity against $5{\alpha}$-reductase. Antioxidant activities were determined by means of, 2, 2-diphenyl-1-picrylhydrazyl (DPPH) assays. All peptides could inhibit $5{\alpha}$-reductase in lipopolysaccharide-stimulated macrophage. In conclusion, DK peptides was suggested as the most attractive ingredients for improving hair loss, because of the high inhibitory against $5{\alpha}$-reductase inhibition.

CCR Expression of Bronchoalveolar Lavage Fluid (BALF) Neutrophils and Chemotactic Activity of BALF

  • Choi, Eu-Gene;Yang, Eun-Ju;Kim, Dong-Hee;Lee, Ji-Sook;Kim, In-Sik
    • Biomedical Science Letters
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    • v.17 no.1
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    • pp.89-93
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    • 2011
  • Asthma is an inflammatory airway disease and is characterized by the releases of inflammatory mediators including chemokines. They are mainly associated with the recruitment, activation and dysregulation of specific inflammatory cells, especially neutrophils in neutrophilic asthma. CC chemokines bind to CC chemokine receptors (CCRs) in the surface of their target cells. The aims of this study are to examine the CCR expression in neutrophils of bronchoalveolar lavage fluid (BALF) of asthmatic patients and to determine the alternation of migration and apoptosis of neutrophils by the BALF. We demonstrate that CCR3 strongly expresses in BALF neutrophils of asthmatic patients as compared to other CCRs and increases during apoptosis of the BALF neutrophils. The migration of asthmatic blood neutrophils increases in response to asthmatic BALF as compared to BALF of normal volunteer. In addition, asthmatic BALF includes the higher levels of IL-8 protein than normal BALF and it has no effect on apoptosis of asthmatic blood neutrophils. Taken together, our results indicate that CCR3 expression may be associated with unknown function of asthmatic BALF neutrophils and BALF may be involved in the recruitment of neutrophils into the airway, but not in the neutrophils apoptosis.

Synthesis of New 2-Iminothiazolines and Their Antifungal Activities (새로운 2-이미노티아졸린 유도체의 합성과 항균 활성(I))

  • Nam, Kee-Dal;Kim, Byung-Sup;Cho, Kwang-Yun;Hahn, Hoh-Gyu
    • Applied Biological Chemistry
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    • v.40 no.2
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    • pp.139-143
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    • 1997
  • This research aims at developing a new pesticide by means of synthesizing new 2-iminothiazoline derivatives and testing their bilolgical activity. In an effort to prepare 2-iminothiazolines, primary amines were treated to have reaction with isothiocyanate, followed by a treatment of ${\alpha}-halo$ ketone derivatives. Their antifungal activaty was tested against six different plant diseases. A compound that has a phenylimino group at C-2, methyl at C-3, phenylcarbamoylmethyl at C-4, and hydrogen at C-5 on the thiazoline skeleton was found to be most active.

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Homeopathic mother tincture of Conium initiates reactive oxygen species mediated DNA damage and makes HeLa cells prone to apoptosis

  • Bishayee, Kausik;Mukherjee, Avinaba;Paul, Avijit;Khuda-Bukhsh, Anisur Rahman
    • CELLMED
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    • v.2 no.3
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    • pp.26.1-26.5
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    • 2012
  • Adverse side-effects and lack of scientific validation of some chemotherapeutic agents prevent the use of many traditional medicines claimed to have anti-cancer effects. Ethanolic extract of Conium maculatum has long been used in traditional and alternative systems of medicine including homeopathy for the treatment of glandular enlargements, cancerous tumours or hard lumps of testicles, prostate, ovaries, breasts and/ or uterus, particularly in the breast. However, if and how it acts still remains scientifically unknown. This study aims to test if Conium extract (CE), used as mother tincture of Conium in homeopathy, has demonstrable anti-cancer potentials without having much cytotoxicity in normal cells. Cytotoxicity of the drug was tested by conducting MTT assay on both normal (peripheral blood mononuclear cells) and HeLa cells. We also evaluated DNA fragmentation and DNA damage by DAPI and diphenylamine assay. The LDH activity assay was done to evaluate the percentages of apoptosis and necrosis. ROS accumulation also was evaluated to pin-point the actual events of apoptosis. Administration of drug clearly demonstrated its anti-cancer potentials as evidenced by the DNA damage analysis. The ROS activity also increased in case of the CE treated cells. LDH data revealed that the mode of cell death was mainly apoptotic and not necrotic. CE appears to induce apoptosis of cancer cells through ROS mediated pathway, and has negligible cytotoxicity against normal cells.

Research of Traditional Herbal Medicines for Anti-aging, Inhibition Effect of Wrinkle and Whitening Effect in the Skin (피부의 노화와 주름 억제, 미백효과를 가지는 전통 한약재의 탐색)

  • Kim, Soo-Hwa;Jung, Hee;Shin, Yong-Cheol;Ko, Seong-Gyu
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.3
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    • pp.691-698
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    • 2008
  • The aims of this study are to search herbal medicines that have anti-aging, anti-wrinkle, anti-oxidant and whitening effects. This is preliminary study as a finding for excellent and specific natural agents which inhibit the skin aging and whitening formation. In this study, the articles and the documents, which have been published in domestically or internationally, have been searched and analyzed. Articles were gathered by taking advantage of Society of Cosmetic Scientists of Korea's documents, Pub med database, Korean Medical Database and Korean Studies Information Service System. Among the many species of herbal medicines, we selected the herbal medicines showing superoxide scavenging activities, and 1.1-diphenyl-2-picrylhydrazyl(DPPH) scavenging effects. The herbal medicines were showed anti-wrinkle effects on Metrixmetallo proteinase (MMP-1) inhibition activity and elastase inhibition activity. Also we found herbal medicines that have highly effect of tyrosinase inhibition, L- DOPA inhibition and melanin synthesis inhibition.