• The Korean Journal of Nuclear Medicine
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• v.29 no.3
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• pp.332-342
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• 1995

This study was designed to evaluate the effects of various factors on the therapeutic effect of the I-131 labeled anti-carcinoembryonic antigen monoclonal antibody(anti-CEA antibody). Tetrazolium-based colorimetric assay (MTT) was used to compare in vitro cytotoxicity of 3 Korean colon cancer cell lines (SNU-C2A, SNU-C4, SNU-C5) for selection of proper 2 cell lines in this study. The changes of the size of tumor which was xenografted to nude mice (balb/c nu/nu) were compared in 4 groups (group treated I-131 labeled anti-CEA antibody, group treated with non-radiolabeled anti-CEA antibody, group treated with I-131 labeled anti-human chorionic gonadotropin monoclonal antibody (anti-hCG antibody) as nonspecific antibody, and group injected with normal saline as a control). Immunohistochemical staining and in vivo autoradiography were performed after excision of the xenografted tumor. The results were as below mentioned. The in vitro cytotoxic effect of I-131 labeled anti-CEA antibody is most prominent in SNU-C5 cell line between 3 cancer cell lines. The changes of xenografted tumor size in both SNU-C4 and SNU-5S cell tumors at the thirteenth day after injection of the antibodies were smallest in the group treated with I-131 labeled anti-CEA antibody (SNU-C4/SNU-C5; 324/342%) comparing with other groups, group treated with anti-CEA antibody (622/660%), group treated with I-131 anti-hCG antibody (538/546%), and control group(1030/724%)(P<0.02 in SNU-C4 and P<0.1 in SNU-C5 at the 13th day after injection of antibodies). On the thirteenth day after injection of the antibodies nude mice were sacreficed to count the radiouptake of tumor and to check the changes of tumor size. Correlations between radiouptake and change of tumor size were calculated in each groups and significant negative correlation was only obtained in the group treated with I-131 anti-CEA antibody (p<0.05). There were no correlations between antigenic expression of carcinoembryonic antigen and distribution of anti-CEA antibody in both SNU-C4 and SNU-C5 cell tumors on immunoperoxidase staining. On in vivo autoradiography the distributions of anti-CEA antibody were heterogeneous and the intensities of binding were various in SNU-C4 and SNU-C5 cell tumors. It is concluded that I-131 labeled tumor-specific monoclonal antibody, anti-CEA antibody is effective in suppressing the xenografted tumor growth and the effect is influenced by sensitivity of tumor cell itself to the radiolabeled antibody and other local factors instead of specificity of antibody.

• Management & Information Systems Review
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• v.37 no.3
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• pp.1-25
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• 2018

This research performed the empirical test for the effects of learning transfer on perceived usefulness, perceived ease of use, self-efficacy and work environment using 390 employees who have experienced e-learning in domestic and foreign companies. Analyzed the mediating effects of self-efficacy and work environment in addition to direct effect of each factor on learning transfer. The results showed that perceived usefulness and perceived ease-of-use of e-learning learner had a positive(＋) effect on self-efficacy and a positive influence on supervisor and peer support and organizational climate. Self-efficacy showed a positive effect on learning transfer, and supervisor support, peer support and organizational climate had a positive influence on learning transfer as well. Perceived usefulness also had a positive effect on learning transfer. However, perceived ease-of-use had no significant effect on learning transfer. As a result of the mediating effect analysis, self-efficacy and work environment were analyzed to have mediating effects between perceived usefulness, perceived ease of use, and learning transfer. The implications of this study are as follows. First, this study designed a new research model that reflects factors influencing the effect of learning transfer on acceptance of e-learning that is common in corporate education. It has derived a research model of perceived usefulness and perceived ease-of-use, which were used as mediating variables for external characteristics factors, as independent variables, using self-efficacy and work environment as mediating variables, which were studied as external factors. Second, most of the studies on technology acceptance model and learning transfer are conducted in a single country. The reliability was enhanced by testing the study models using different samples from 26 countries. Third, perceived usefulness and ease-of-use in existing studies have been considered as key determinants of acceptance intention and learning transfer. This study explored the mediating effects of learner and environmental factors on the accepted information technology and strengthened and supplemented the path of learning transfer of perceived usefulness and ease-of-use. In addition, based on the sample analysis of various countries used in this study, it is expected that future international comparative studies will be possible.

• Journal of the Korean Chemical Society
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• v.33 no.5
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• pp.558-567
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• 1989

The synthesis of methanol from carbon dioxide and hydrogen was studied for various compositions of Cu/ZnO catalyst system. Effect of the composition ratio of CuO and ZnO on the catalytic activity in the above reaction and the relationship between the activity and the characteristics of the catalysts were explained from the result of surface area measurements, SEM, XRD, and XPS. The major products of the reaction were methanol and carbon monoxide. The selectivity to methanol increased with increase of the copper oxide content in the catalyst up to CuO: ZnO = 30:70 weight ratio, and decreased rapidly when the content is above 70%. SEM and BET measurements, indicate that this point corresponds to the increasing point of the catalyst crystallite size and the decreasing point of the surface area. As to the Cu/Cu + Zn atomic ratio, the surface concentration of copper measured by XPS decreased remarkably when the copper oxide content in catalyst was higher than 50%. All the unreduced catalysts had almost same binding energy of Cu(2P3) level, but the binding energy for $Cu(2P^3)$ level of reduced catalysts was lowered than that of calcined catalysts. The surface copper species which was in the maximum amount when the CuO:ZnO composition in the catalyst was 30:70, existed as zero valent copper. This result agreed with the experimental result that the highest rate of methanol formation was observed when the CuO content in the catalyst was 30%. It was postulated that these reduced catalysts performed with a relatively strong basicity because the formation rate of acetone was higher than that of propylene in isopropanol decomposition as measured in a pulse type reactor.

• The korean journal of orthodontics
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• v.40 no.5
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• pp.304-313
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• 2010

Objective: The aim of this study was to evaluate the occlusal force and contact area and to find its associating factors in Koreans. Methods: Occlusal force and contact area in maximum intercuspation were measured using the Dental $Prescale^{(R)}$ system in 651 subjects (15 with normal occlusion, 636 with various malocclusions divided into subgroups according to the skeletal pattern, Angle's molar relationship, age and gender). Results: Occlusal force of the normal occlusion group ($744.5{\pm}262.6N$) was significantly higher than those of the malocclusion group ($439.0{\pm}229.9N$, $p$ < 0.05). Occlusal force was similar regardless of differences in ANB angle or Angle's molar classification, however the increase in vertical dimension significantly reduced occlusal force ($p$ < 0.05). Conclusions: Occlusal force was significantly lower in the malocclusion group compared to the normal occlusion group, and in females compared to males, but it was not affected by age, antero-posterior skeletal pattern or molar classification. Although a hyperdivergent facial pattern indicated lower occlusal force compared to a hypodivergent facial pattern, the differences in skeletal pattern were not the primary cause of its decrease, but a secondary result induced by the differences in occlusal contact area according to the facial pattern.

• Journal of The Korean Association For Science Education
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• v.38 no.5
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• pp.681-691
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• 2018

The purpose of this study is to investigate the impacts of Collaborative Problem solving for Character competency (CoProC) strategy on the practical character competency and collaborative problem solving competency in middle school. For this study, 49 seventh grade students (two classes) were selected for use applying the CoProC strategy (CoProC group) while 46 students (two classes) were used for traditional lecture and experimental class (comparative group). In the result, CoProC group showed a statistically significant result in practical character competency than the comparative group. In the sub items of the competency, the CoProC group showed result statistically significant in cooperation, communication, responsibility, and positive self-understanding than the comparative group. Analysis of the effect size of students' practical character competency showed that the CoProC group results showed more effective than the comparative group in terms of care, cooperation, communication, honesty, responsibility, positive self-understanding, and self-regulation. In addition, we investigated the effect of the CoProC strategy on collaborative problem solving competency. As a result, it showed a large effect in the total score of collaborative problem solving competency. Among the sub items of the competency, 'exploration and understanding of members' showed a small size of effect and 'Establishing and maintaining team organization' showed a medium size of effect. 'Communication' and 'self-reflection' showed a large effect. CoProC strategy embedded in Science subject could improve students' collaborative problem solving competency through the process of scientific communication in the scientific inquiry process.

• Korean journal of applied entomology
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• v.25 no.3 s.68
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• pp.133-138
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• 1986

This study was conducted to compare the methods of slide dip and leaf dip techniques in the resistant level determination of spider mites to acaricides used; .and to investigate resistant levels of two-spotted spider mite, Tetranychus urticae Koch to benzomate, dicofol and cyhexatin in Honam region of Korea. Comparisons of the resistant strains and susceptible strain based on $LC_{50}$ values were summarized. Using the slide dip and leaf dip techniques with benzomate acaricide, the Keumchun strain of T. urticae showed 75-and 69-fold resistant levels, respectively, as compared with the Kwangju susceptible strain, but the Hackyo strain was 38-and 35-fold resistant levels, respectively. There was no significant difference (P>0.05) between the slide dip and leaf dip methods. With dicofol acaricide, resistant levels of the Keumchun strain of T. urticae were 71 times by using the slide dip and 74 times by using the leaf dip as resistant as the Kwangju susceptible strain while the Hackyo strain was 24 times by the former method and 23 times by the later method. There was also no significant difference (P>0.05) between both the methods. The slide dip technique is more recommendable than the leaf dip technique for determination of degree of chemical resistance to the spider mites with accuracy and less variation of the results. Using the slide dip method with cyhexatin, the Bia, Keumchun and Hackyo strains of T. urticae were 19-, 18- and 9-fold resistant levels, respectively, over the Kwangju susceptible strain.

• Korean journal of applied entomology
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• v.20 no.3 s.48
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• pp.135-145
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• 1981

Vegetables including Chinese cabbage and radish have been grown in alpine areas such as Muju, Namweon, Jinan and Jangsu during the shortage period of vegetables. The incidence of various diseases, environmental factors such as temperatures and rainfalls, and aphid populations as virus vector were observed at 10-day intervals from July to September in those areas. Disease incidence showed no significant difference among locations. Major diseases in Chin ese cabbage were bacterial soft rot, white spot, downy mildew, mosaic virus, Alternaria leaf spot and Fusarium seedling blight. Major diseases in radish were virus, white rust, black rot, root rot, leaf spot and Fusarium seedling blight. Disease incidence reached peak on Aug. 20 with $27\%$ infection in radish and with $20\%$ infection in Chinese cabbage during the growing season, and declined thereafter. Percentage of infection in each growth stage showed $25\%$ at root thickening stage and $26\%$ at the harvest time in radish; and the head formation stage, $24\%$ at the harvest time. The data indicate that disease incidence in radish increased rapidly at late growing stage and progressively increased in Chinese cabbage Seedling blight caused by Fusarium sp. and root rot caused by Aphanomyces sp. were also observed in those areas. Cool and wet weather appeared to be favorable for disease incidences during the rainy period of growing season although average temperature was about $25^{\circ}C$. Populations of aphids were lower in the alpine vegetable growing area than that of flat areas. Aphids as virus vectors from total aphids collected were $73.5\%$ or 289 virus vectors /993 total aphids in Namweon and $18.1\%$ or 31 virus vectors/171 total aphids in Muju. The most prerevalent species of aphids was Myzus persicae Sulz.

• Journal of the Korean Ceramic Society
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• v.41 no.11
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• pp.834-841
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• 2004

The purpose of this study is to investigate the properties of traditional Korean ash glazes by using locally available sources; 10 kinds of grain stems,2 kinds of husks (pod, chaff), and 4 kinds of vegetables (spinach, radish leaf and stem, pumpkin leaf and stem, pepper stem), and to develop their practical uses as ash glazes. The test results of these ash glazes indicate that these ashes can be classified into four categories. The first group, which includes perilla stem ash, sesame stem ash, black bean stem ash and red-bean stem ash, shows strong milky white due to relatively lower content of $SiO_2$, and relatively higher content of CaO and P$_2$O$\_$5/ content (10% higher than others), and their glazes were found to be suitable for opaque glaze as they show relatively stable bright greenish color. The second group includes pepper stem ash, spinach ash, pod ash, radish leaf and stem ash, and bean stem ash, and this group was found to contain even quantity of every component. And their glaze show somewhat greenish color because of especially high content of MgO and more than 2% of Fe$_2$ $O_3$. They were found to be suitable for basic glaze of IRABO glaze. The third group, which includes com stalk ash, white bean ash, pumpkin leaf and stem ash, has more $SiO_2$ and Al$_2$ $O_3$ than other ashes, and it also contains 3～5% of Fe$_2$ $O_3$. As a result of those components, this third group shows the greatest change of color and chroma, and was found to be suitable glazes as basic glaze of Temmoku and black glazes. The fourth group (reed ash, rice straw ash, indian millet stalk ash and chaff ash) has as much as 45～82% of $SiO_2$ and relatively lower content of Fe$_2$ $O_3$ and P$_2$ $O_3$. This group shows blue or greenish white color, and was found to be suitable as the basic glaze of white glaze.

• Applied Microscopy
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• v.34 no.1
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• pp.31-42
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• 2004

Acute respiratory distress syndrome (ARDS) is a kind of acute lung injury characterized by inflammatory disruption of alveolar-capillary barrier and notorious for its high mortality. Neutrophils cause cell damage through the production of free radicals, inflammatory mediators, and proteases in ARDS. $PLA_2$ might serve a primary regulatory role in the activation of neutrophils. This present study was performed to elucidate the effect of rutin known as $PLA_2$ inhibitor on ARDS induced by endotoxin. Endotoxin had increased lung myeloperoxidase (MPO) activity, BAL (bronchoalveolar lavage) protein content, numbers of neutrophils in BALF (bronchoalveolar lavage fluid) compared with those of control rat (p<0.001). In addition, histological evidence of lung injury was correlated with neutrophil influx into alveolar space and cerrous perhydroxide granules were found in lining of endothelial cell, alveolar type I, II cells. In contrast, pretreated group of rutin had significantly decreased all of the parameters (p<0.001). These data suggest that inhibition of $PLA_2$ is one step approach that block the process of ARDS. Accordingly, we conclude that rutin can be used as the prophylactic agent for ARDS on the bases of these experimental results.

• Korean Journal of Psychosomatic Medicine
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• v.8 no.1
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• pp.46-57
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• 2000

Objectives : The purpose of the present study was to examine the effect of subacute treatment with the selective serotonin reuptake inhibitors(paroxetine and sertraline) on immobility in the forced swim test(FST) and on FST-induced changes in immune parameters of the mice. Methods : Authors applied a modified method of FST by Porsolt et al. Over 5 BALB/c mice were used for each group of experiments. To explore the changes in immune parameters by FST, authors investigated the production of anti-rat RBC antibody, concanavalin A(ConA)- or lipopolysaccharide(LPS)-stimulated splenocytes proliferation assay and cytokine gene expression. Results : Both paroxetine and sertraline decreased the duration of immobility in a dose-related manner. FST-performed mice showed a significant decrease in mitogenic responses of splenocytes and a slight increasing tendency in anti-rat RBC antibody response. All these responses were attenuated significantly by paroxetine and attenuated nearly nominal significance level by sertraline. The cytokine profiles of ConA-stimulated splenocytes from FST-performed mice showed stronger expression of IL-4 and weaker expression of IL-2 than control mice, and no changes in the expressions of IFN-$\gamma$ and lymphotoxin. IL-6 and IL-10 were not expressed in both group of mice. The pretreatment of paroxetine and sertraline attenuated the altered cytokine expressions in FST-performed mice to some extent. Some alterations of the expressions of IL-6 and IL-10 were observed in the mice which the selective serotonin reuptake inhibitors had been pretreated. Conclusion : The subacute treatment of paroxetine and sertraline attenuated the FST-induced behavioral and immune changes, and these serotonin reuptake inhibitors may exert some modulating effects on the immune system by the induction of cytokine gene expression, especially IL-6 and IL-10.