• Journal of Conservation Science
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• v.38 no.3
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• pp.217-233
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• 2022

The remains found in Geumcheok-ri, Gyeongju are located in close proximity to the Ancient Tombs in Geumcheok-ri, Gyeongju (Historic Site) which were built between the late 5th and early 6th centuries, and these tombs are known to belong to the powerful rulers of that area. Using metallurgical techniques, this study was conducted on the iron objects obtained from the excavated remains in Geumcheok-ri, Gyeongju which are presumed to have a close relation to the nearby ruins that played an important role in the growth of Silla. To identify differences in manufacturing techniques based on the purpose of the iron objects, eight objects were selected after classifying them by use and the microstructure and non-metallic inclusions were investigated. The analyses results confirmed that the manufacturing process involved forging iron with a high or low carbon content to produce a particular shape, and that the carburization process was applied to iron post forging a shape to increase its strength when necessary. The mechanical properties were improved by selectively applying the steelmaking method and the heat treatment technique considering the functions of the parts, and the low temperature reduction was applied to the smelting process. Furthermore, in comparison with the iron objects excavated from the remains located in the center of Gyeongju and its outskirts, it is confirmed that there is similarity in the smelting and manufacturing techniques between these objects.

• Journal of The Korean Society of Integrative Medicine
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• v.10 no.3
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• pp.85-94
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• 2022

Purpose : This study aimed to investigate the effects of 12 weeks of resistance exercise on body composition, physical strength, blood lipids, and insulin. Methods : The study was conducted on 24 elderly women divided into two groups: 12 subjects in an exercise group and 12 subjects in a control group. Resistance exercise was performed for 50 minutes a day, three times a week, for the duration of 12 weeks, and body composition, physical strength, blood lipids, and insulin were measured before and after the subjects completed the program. For the statistical analysis, the mean and standard deviation (M±SD) of each variable were calculated using SPSS version 20, and a paired t-test and two-way repeated ANOVA were conducted to test for the differences before and after the resistance exercise. All significant levels were set to α=.05 as a result of the experiment. Results : Changes in body composition after the 12-week resistance exercise program did not show any significant difference based on the comparison between the groups, but when noting the values for body fat percentage and body in the control group before and after, a significant difference was shown in fat mass (p<.05). As for changes in physical fitness, significant differences appeared in flexibility, muscle strength, and stenotic force (p<.01) when the groups were compared. Regarding pre- and post-values within each group concerning flexibility within the exercise group, significant differences were shown in gender (p<.001), muscle strength (p<.05), (p<.01), muscle earth strength, equilibrium (p<.01), stenosis force, and cardiopulmonary earth force (p<.001). Also, comparisons between populations in changes in blood lipids the values before and after in each group, significant differences in glucose (p<.05) and insulin (p<.05) were shown in the exercise group. When comparing the values before and after in each population, a significant difference was shown in the control group (p<.05). Conclusion : When all the results were integrated, the 12-week resistance exercise program was found to enhance physical strength (flexibility, muscle strength, and coordination) and improve the blood sugar levels of elderly women. In particular, resistance exercise is believed to lower the prevalence of obesity, type 2 diabetes mellitus, and metabolic diseases by having a positive effect on insulin. Further studies are suggested to verify the effect on body composition and blood lipids by setting up a variety of exercise treatment methods (including subjects, exercise periods, exercise plans, and exercise intensity focuses).

• Journal of the Korean Society of Earth Science Education
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• v.15 no.2
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• pp.132-141
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• 2022

The purpose of this study is to investigate the effect of science classes using elementary school distance science classes on science academic achievement and creative personality. The research group and non-research group were selected for 6th grade elementary school students. After 10 weeks of experimental treatment, science classes were conducted with the contents of the elementary school science section, 'Changes of the seasons'. In the three domains of 'knowledge', 'inquiry', and 'attitude', which are sub-domains of science academic achievement, as a result of the pre-post test, there was a positive effect in 'inquiry' and 'attitude', which are sub-domains of science academic achievement. However, it was found that there was no positive effect in 'knowledge', a sub-domain of academic achievement. However, it was found that there was a positive effect in the overall test result of academic achievement. Therefore, it is interpreted that science classes using elementary school distance science classes had an effect on academic achievement. There was a significant effect in the sub-domains of the creative personality test, 'persistence/obsession', 'self-confidence', 'humor', 'imagination', 'openness', 'adventure', and 'independence'. However, it was found that there was no effect in the sub-domain 'curiosity'. The overall test results of the creative personality test showed a significant effect. Therefore, it is interpreted that science classes using elementary school distance science classes are effective in cultivating creative personality. Students' perceptions of science classes using elementary school distance science classes also showed positive responses.

• Proceedings of the KSAR Conference
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• 2001.03a
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• pp.76-76
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• 2001

The objective of this study was to optimize the vitrification method of in vitro produced bovine embryos. Thus, in vitro produced embryos at 8 cell, morula and blastocyst stages were vitrified on electron microscope grids (EM grids) or in open pulled straws (OPS) with EG5.5 (5.5 M ethylene glycol, 1.0 M sucrose and 10% FBS in m-DPBS medium) freezing solution and their survival rates after thawing were compared. The embryos on EM grids or in OPS were briefly exposed to EG5.5 freezing solution and plunged directly into liquid nitrogen within 30 to 35 sec. Post-thawed embryos were serially diluted in 0.5, 0.25 and 0.125 M sucrose in m-DPBS, each for 1 min, and then cultured in CRI aa medium supplemented with 10% FBS. Embryonic survival rate was assessed as re-expanded and hatched rates of those embryos after warming. The rates of re-expansion embryos did not significantly different between EM grid (8 cell: 42.10%, morula: 66.66% and blastocyst: 77.08%) and OPS (8 cell: 47.36%, morula: 61.90% and blastocyst: 83.33%) methods. In addition, the hatched rates in EM grid (8 cell: 31.57%, morula: 57.14% and blastocyst: 72.91%) were similar to those in OPS (8 cell. 34.21%, morula: 50.00% and Blastocyst: 77.08%). Interestingly, even at the same blastocyst stage, the in vitro survival of day 7 embryos (EM grid: 79.48 and OPS: 87.18%) was higher than those of day 8 embryos (EM grid: 72.10 and OPS: 82.06%). The total cell number of blastocyst developed in vitro after vitrification was examined with Hoechst 33342 staining to compare the embryo quality among different treatment groups. The total cell number of blastocyst was not significantly different between vitrified groups (EM grid: 162.4$\pm$8.0 and OPS: 158.4$\pm$7.1) and unvitrified control (168.0$\pm$5.6). These results indicate that both vitrification containers can provide the high rate of embryo survival. Moreover, the OPS container may not need a cap to protect the container from floating after immersion in L$N_2$. Therefore, this study suggest that bovine embryos can be cryopreserved easily, effectively and successfully by vitrification method using EM grid or OPS with EG5.5 freezing solution. In the future, the Pregnancy rate would be investigated after transfer of our vitrified embryos into the appropriated recipients.

• The Korean Journal of Coaching Psychology
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• v.7 no.2
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• pp.21-46
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• 2023

The current study aimed to develop and evaluate the effectiveness of a group coaching program to improve college students' career exploration behaviors based on the self-affirmation theory. Participants were undergraduate students at a University in Seoul and volunteered in the program during the break. The group coaching program was conducted twice a week during three weeks, a total of six times, and each session lasted 2 to 2.5 hours. In this study, the effect of self-affirmation embedded in the group coaching program on various psychological variables and college students' career exploration behaviors were examined. A mixed-randomized analysis was conducted to compare the pre, post, and follow-up tests of the experimental, comparison, and no-treatment control groups, each consisting of 18 participants. The results showed that participants in the experimental group coaching condition showed more significant improvements in psychological resources, career self-efficacy, openness, problem-focused coping, and career exploration behaviors compared to the comparison and control groups, and these results were maintained even after the program ended. The implications of this study for coaching theory and practice, as well as limitations and future research directions, were discussed.

• Parasites, Hosts and Diseases
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• v.61 no.3
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• pp.282-291
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• 2023

Despite the recent progress in public health measures, malaria remains a troublesome disease that needs to be eradicated. It is essential to develop new antimalarial medications that are reliable and secure. This report evaluated the pharmacokinetics and antimalarial activity of 1,2,6,7-tetraoxaspiro[7.11]nonadecane (N-89) using the rodent malaria parasite Plasmodium berghei in vivo. After a single oral dose (75 mg /kg) of N-89, its pharmacokinetic parameters were measured, and t_1/2 was 0.97 h, T_max was 0.75 h, and bioavailability was 7.01%. A plasma concentration of 8.1 ng/ml of N-89 was maintained for 8 h but could not be detected at 10 h. The dose inhibiting 50% of parasite growth (ED₅₀) and ED₉₀ values of oral N-89 obtained following a 4-day suppressive test were 20 and 40 mg/kg, respectively. Based on the plasma concentration of N-89, we evaluated the antimalarial activity and cure effects of oral N-89 at a dose of 75 mg/kg 3 times daily for 3 consecutive days in mice harboring more than 0.5% parasitemia. In all the N-89-treated groups, the parasites were eliminated on day 5 post-treatment, and all mice recovered without a parasite recurrence for 30 days. Additionally, administering oral N-89 at a low dose of 50 mg/kg was sufficient to cure mice from day 6 without parasite recurrence. This work was the first to investigate the pharmacokinetic characteristics and antimalarial activity of N-89 as an oral drug. In the future, the following steps should be focused on developing N-89 for malaria treatments; its administration schedule and metabolic pathways should be investigated.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.92-92
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• 2002

Considerable attention has been focused on the cryopreservation of semen and estrus induction in dog, as consequence of poor productivity caused by long anestrus period, in order to enhance the productivity of youngs and to preserve the breeds. The objectives of this study were to evaluate semen quality after cryopreservation and to evaluate the Pregnancy rate after insemination (AI). Fifty infertilie dogs (age 2∼3 years) were selected for the study and divided into three different estrus induction treatment groups. Group 1: dogs (n=15) were given clomifene (0.1 mg/kg) orally for five days at 12 hr intervals. Group 2: dogs (n=15) were given bromocriptine (50 $\mu\textrm{g}$/kg) orally for five days at 12 hr intervals, followed by single injection intravenously of 500 IU GnRH (Group 3, n=20) when pro-estrus occurred. The rates of pregnancy in estrus inducted dogs mated naturally compared to those inseminated artificially with ejaculated fresh semen and frozen-thawed semen. Estrus detection was performed using the method of vaginal smear and confirmed by the plasma progesterone assay. The ejaculated semen to freeze was exposed to a mixture of Tris extender with cryoprotectant (Trisma, 81 mM: TES, 209 mM: citric acid, 6 mM; glucose, 5 mM; glycerol, 8%) and cryopreserved gradually by slow-cooling at 17 cm above the surface of liquid nitrogen (LN$_2$) for 23 min. The motility of frozen-thawed spermatozoa was assessed by phase-contrast microscopy. To assess their viability and acrosome content, spermatozoa were stained with a vital stain and Fluorescence conjugated lectin Pisum Savitum Agglutinin (FITC/PAS), respectively. Pregnancy was confirmed by ultrasonograpy on day 25, 35 and 55 post insemination. The use of fresh semen, the pregnancy rates were observed 66.6, 66.6, 75.0 and 83.3% in natural estrus, clomifene induced, bromocriptine induced and a combination of GnRH and bromocriptine, respectively. The use of frozen-thawed semen, the pregnancy rates were observed 66.6, 33.3, 50.0 and 60.0% in natural estrus, clomifene induced, bromocriptine induced and a combination of GnRH and bromocriptine, respectively. No difference was observed in the number of offspring produced among natural estrus and treated groups inseminated with fresh or frozen-thawed semen. In conclusion, the pregnancy rate of dogs treated with a combination of GnRH and bromocriptine was more effective than use of clomifene or bromocriptine only. In addition, frozen-thawed semen can be used successfully far artificial insemination in dog.

• Parasites, Hosts and Diseases
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• v.61 no.1
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• pp.33-41
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• 2023

The discovery of new antimalarial drugs can be developed using asynchronized Plasmodium berghei malaria parasites in vivo in mice. Studies on a particular stage are also required to assess the effectiveness and mode of action of drugs. In this report, we used endoperoxide 6-(1,2,6,7-tetraoxaspiro [7.11] nonadec-4-yl) hexan-1-ol (N-251) as a model antimalarial compound on P. chabaudi parasites. We examined the antimalarial effect of N-251 against ring-stage- and trophozoite-stage-rich P. chabaudi parasites and asynchronized P. berghei parasites using the 4-day suppressive test. The ED₅₀ values were 27, 22, and 22 mg/kg, respectively, and the antimalarial activity of N-251 was verified in both rodent malaria parasites. To assess the stage-specific effect of N-251 in vivo, we evaluated the change of parasitemia and distribution of parasite stages using ring-stage- and trophozoite-stage-rich P. chabaudi parasites with one-day drug administration for one life cycle. We discovered that the parasitemias decreased after 13 and 9 hours post-treatment in the ring-stage- and trophozoite-stage-rich groups, respectively. Additionally, in the ring-stage-rich N-251 treated group, the ring-stage parasites hindered trophozoite parasite development. For the trophozoite-stage-rich N-251 treated group, the distribution of the trophozoite stage was maintained without a change in parasitemia until 9 hours. Because of these findings, it can be concluded that N-251 suppressed the trophozoite stage but not the ring stage. We report for the first time that N-251 specifically suppresses the trophozoite stage using P. chabaudi in mice. The results show that P. chabaudi is a reliable model for the characterization of stage-specific antimalarial effects.

• Journal of the Korean Orthopaedic Association
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• v.52 no.1
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• pp.73-82
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• 2017

Purpose: To assess the chronological changes of disease-related kyphosis after chemotherapy alone. Materials and Methods: A total of 101 children aged 2 to 15 years with spinal tuberculosis, accompanied by various stages of disease processes were enrolled for analysis. By utilizing the images in them, the growth plate condition and chronological changes of kyphosis after chemotherapy were analyzed at two points in time; the first assessment was at post-chemotherapy one-year and second at the final discharge. Results: Complete disc destruction in the cervical, dorsal and lumbosacral spines was observed in 2 out of 40 children (5.0%), 8 out of 30 children (26.7%), and 6 out of 31 children (19.4%), respectively. In those cases, the residual kyphosis inevitably developed. In the remaining children, the discs were intact or partially damaged. Among the 101 children kyphotic deformity was maintained without change in 20 children (19.8%). Kyphosis decreased in 14 children (13.9%), while it increased in 67 children (66.3%) with non-recoverably damaged growth plate. Conclusion: Although it is tentatively possible to predict the deformity progress or non-progress and spontaneous correction at the time of the initial treatment, its predictive accuracy is low. Therefore, assessment of the chronological changes should be performed at the end of chemotherapy. In children with progressive curve change, assessment of deformity should be continued until maturity.

• 한국체육학회지인문사회과학편
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• v.55 no.4
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• pp.507-516
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• 2016

The purpose of this study is to identify the effects of PPARβ/δ over-expression on PGC-1α mRNA and protein stability after single bout of swimming exercise in mice skeletal muscle. Empty vector (EV) or PPARβ/δ was over-expressed in tibialis anterior(TA) using electroporation(EPO) technique to compare with non-treatment muscle(control; Con). TA muscles were dissected at 0h, 24h or 54h after termination of exercise. PGC-1α mRNA in Con, EV and PPARβ/δ over-expressed muscles were increased 6.8 fold (p<.001), 6.2 fold(p<.001) and 7.1 fold(p<.001), respectively, than sedentary(Sed) group at 0h after exercise and then reverted to Sed group levels at 24h and 54h after termination of exercise. PGC-1α and PGC-1α ubiquitination in EV treated muscles were increased 2.2 fold and 1.74 fold, respectively, than Sed group at 24h after termination of exercise, and then reverted to Sed group levels at 54h after termination of exercise. PGC-1α in PPARβ/δ over-expressed muscles at 24h and 54h after termination of exercise were increased 2.5 fold and 2.2 fold, respectively, than Sed group, but PGC-1α ubiquitination was not increased at 24h and 54h after termination of exercise. Our results indicate that PPARβ/δ over-expression does not increase PGC-1α mRNA stability, but increase PGC-1α protein stability through post-translation mechanism after termination of exercise.