• The Mathematical Education
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• v.42 no.1
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• pp.19-39
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• 2003

The purpose of this study is to find out effective ways to take care of the 8th and 10th graders' disposition causing math. disliking. To accomplish this goal, we proceeded as follows : First we categorized the 11 factors recognized as the reasons of math. disliking into 4 math. disliking causes such as psychological f: environmental cause, conceptual cause, relational cause and application related cause. Second, to take care of these tow causes, we developed materials which are closely related with the contents of the 8th and 10th graders' school mathematics. Third with these materials we taught the students who had proved to have the math. disliking trend, for one semester. As a consequence of this experiment we arrived at the following results. As for psychological & environmental causes, 35.7% of the 8th graders and 17% of the 10th graders proved to have been improved significantly. This result shows that the curing of the psychological & environmental causes is more effective in the 8th graders than in the 10th graders. i.e., the curing effects of the students' psychological & environmental cause for disliking math. decline as they get older. As for conceptual causes, 35% of the 5th graders and 30% of the 10th graders proved to have been improved significantly. In case of the 8th graders this ratio was similar to that of the other causes. But as for the 10th graders this ratio was a little low compared with that of the case of relation causes and application related causes. As for relational causes, 35% of the 5th graders and 49% of the 10th graders proved to have been improved significantly. Especially the 10th graders improved greatly. Among the four factors that compose this cause, especially hierarchy and connection factors were effectively cured. On application related causes, 47% of the 5th graders and 57% of the 10th graders proved to have been cured significantly. And among the four types of causes listed above, this was the most successfully cured one. Of the two factors of this cause, the basic application factor appeared to have been improved in all experimental groups. In connection with teaching methods, we found out the followings two facts. First, the more teachers push students to solve their tasks with their own efforts, the higher is the ratio of owe. Second, the more teachers teach students personally, the more effective are the teaching results.

• IMMUNE NETWORK
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• v.15 no.2
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• pp.100-109
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• 2015

Controlling balance between T-helper type 1 (Th1) and T-helper type 2 (Th2) plays a pivotal role in maintaining the biological rhythm of Th1/Th2 and circumventing diseases caused by Th1/Th2 imbalance. Interleukin 4 (IL-4) is a Th2-type cytokine and often associated with hypersensitivity-related diseases such as atopic dermatitis and allergies when overexpressed. In this study, we have tried to elucidate the function of 1-palmitoyl-2-linoleoyl-3-acetyl-rac-glycerol (EC-18) as an essential modulator of Th1/Th2 balance. EC-18 has showed an inhibitory effect on the production of IL-4 in a dose-dependent manner. RT-PCR analysis has proved EC-18 affect the transcription of IL-4. By analyzing the phosphorylation status of Signal transducer and activator of transcription 6 (STAT6), which is a transcriptional activator of IL-4 expression, we discovered that EC-18 induced the decrease of STAT6 activity in several stimulated cell lines, which was also showed in STAT6 reporter analysis. Co-treatment of EC-18 significantly weakened atopy-like phenotypes in mice treated with an allergen. Collectively, our results suggest that EC-18 is a potent Th2 modulating factor by regulating the transcription of IL-4 via STAT6 modulation, and could be developed for immune-modulatory therapeutics.

• IMMUNE NETWORK
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• v.5 no.2
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• pp.68-77
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• 2005

Background: Costimulation is a critical process in Ag-specific immune responses. Both B7.1 and CD28 molecules have been reported to stimulate T cell responses during antigen presentation. Therefore, we tested whether Ag-specific immune responses as well as protective immunity are influenced by coinjecting with B7.1 and CD28 cDNAs in a mouse HSV-2 challenge model system. Methods: ELISA was used to detect levels of antibodies, cytokines and chemokines while thymidine incorporation assay was used to evaluate T cell proliferation levels. Results: Ag-specific antibody responses were enhanced by CD28 coinjection but not by B7.1 coinjection. Furthermore, CD28 coinjection increased IgG1 production to a significant level, as compared to pgD+pcDNA3, suggesting that CD28 drives Th2 type responses. In contrast, B7.1 coinjection showed the opposite, suggesting a Th1 bias. B7.1 coinjection also enhanced Ag-specific Th cell proliferative responses as well as production of Th1 type cytokines and chemokines significantly higher than pgD+pcDNA3. However, CD28 coinjection decreased Ag-specific Th cell proliferative responses as well as production of Th1 types of cytokines and chemokine significantly lower than pgD+pcDNA3. Only MCP-1 production was enhanced by CD28. B7.1 coimmunized animals exhibited an enhanced survival rate as well as decreased herpetic lesion formation, as compared to pgD+pcDNA3. In contrast, CD28 vaccinated animals exhibited decreased survival from lethal challenge. Conclusion: This study shows that B7.1 enhances protective Th1 type cellular immunity against HSV-2 challenge while CD28 drives a more detrimental Th2 type immunity against HSV-2 challenge, supporting an opposite role of B7.1 and CD28 in Ag-specific immune responses to a Th1 vs Th2 type.

• Applied Microscopy
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• v.21 no.2
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• pp.96-116
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• 1991

The authors studied the morphological distinctions of each of the epidermal layers and the time of appearance of the keratohyalin granules and tonofilaments by the processing of development. The skins were obtained from fetal rats at the age of 14th, 16th, 17th, 18th, 19th and 20th day of gestation, of 1st and 3rd day of neonatal life and of 4th week after birth. The specimens were staind with uranyl acetate and lead citrate. The results obtained were as follows. 1. On the 16th-gestation day, the intermediate layer which contained numerous ${\alpha}-and\;{\beta}$-glycogen particles was appeared, and hemidesmosomes and desmosome were observed as well. 2. Tonofilaments were first observed on the 17th gestation day. 3. Above-mentioned intermediate layer was differentiated into the granular layer and the spinous layer on the 18th-gestation day. Keratohyaline granules were appeared in association with the ribosomes and the tonofilaments and the compound granules were lipoid granules which were surrounded by ribosomes at the periphery. 4. Ultimately, keratinization began to take place from the 20th-gestation day. At the age of 4th week, the thickeness of epidermis and the amount of keratohyaline granule and tonofibrils were decreased. It is consequently suggested that in the differentiation process of the rat epidermis, keratinization begins after formation of hemidesmosomes and desmosomes, from which the tonofilaments are formed and after keratohyaline granules are formed. Therefore appearance of the keratohyaline granules and formation of the tonofilament appears to have a close relations with the keratinization process of the rat epidermis.

• The korean journal of orthodontics
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• v.14 no.1
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• pp.173-183
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• 1984

The author has observed the effects of collagenase on the relapse phenomenon and the histochemical changes during the relapse period. 50 rats were used. : 3rats as a normal group, 15rats as control groups, and 32rats as experimental groups. Rat's teeth were moved for 10days with helical spring applied, followed by injection of "collagenase in Hank's sol." to the experimental groups and the "Hank's sol." to the control group in the interdental gingiva on the 10th day, and the spring was removed on the 11th day. After injection, the experimental animals were sacrificed on the 11th, 13th, 15th, 17th, 20th, and 24th day and prepared histochemically for the Hematoxylin-Eosin, Van-Gieson, and Methyl Green-pyronin staining. The results are as follows: 1. Group I (11th day): In the control group the supracrestal fibers were stretched and the metabolic rate was high. Experimental group showed that supracrestal fibers were resor, bed, disarrayed, and the metabolic rate was low. 2. Group II (13th day): In the control group, the supracrestal fibers began to change from the vertical direction to tooth-axis to the parallel. Experimental group showed that supracrestal fibers were completely resorbed. 3. Group IV (17th day): The control group showed almost normal structure. Form this group the metabolic rates were low. Experimental group showed the most destructive pattern. 4. Group VI (24th day): Experimental group showed almost normal structure. It follows that experimental groups were relapsed less than the control groups, and collagenase was effective in the prevention of relapse after rat's experimental tooth movement.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.4
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• pp.355-361
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• 1998

The purpose of this study was to examine the effects of the fibrin adhesive (Beriplast$^{(R)}$) on healing of full-thickness wounds in the rat's hard palate. Twenty Spraque-Dawley strain white male rats, each weighing 250~300 gm were used. Creation of full-thickness wounds of $4{\times}4mm$ in size were performed on the hard palate. Beriplast$^{(R)}$, a wound dressing material, was applied immediately in the experimental group, but not applied in the control group. All wounds were protected with palatal resin splints. The animals were sacrificed on the 2nd, 4th, 7th, 14th, and 28th day after the operation for macroscopic and microscopic examinations. Results obtained were as follows ; 1. On the 7th day after the operation, epithelial proliferation was greater in the experimental group than that in the control group. 2. The inflammatory reaction of the experimental group was less than the control group on the 2nd and 4th day after the operation. Beriplast was resorbed on the 7th day after the operation. 3. In the control group, the epithelial proliferation occurred from the 7th to the 14th day after the operation, and in the experimental group, epithelial proliferation occurred from the 4th day after the operation. 4. On the 14th and 28th day after the operation, there was no prominent difference between the two groups in histological findings. These results suggest that the use of fibrin adhesive (Beriplast$^{(R)}$) as a palatal wound dressing results in greater epithelial proliferation and less inflammation in the early stage of wound healing.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.23 no.1
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• pp.71-85
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• 1993

The purpose of the study was to investigate the effects of the single and fractionated irradiation on the microvascular structure of the submandibular gland in rats. For this study, 90 Sprague-Dawley strain rats were irradiated to their neck region with equal split doses of 9Gy for a 4 hours interval and 15Gy single dose by 6MV X-irradiation and sacrificed on the 1st, 3rd, 7th, 14th and 27th day after irradiation. The author observed histological changes at Hematoxylin and Eosin staining and PAS staining under a light microscope, and also observed distribution and structural changes of the microvasculature in rat submandibular gland using a scanning electron microscope by forming vascular resin casting. The results were as follows: 1. In the light microscopic examination, the microvasculature was slightly dilated and decreased in number on the 1st day after irradiation, and increase in number of microvasculature was observed on the 3rd day after irradiation. And then distribution of microvasculature was markedly increased on the 7th day after iradiation, but decreased on th 14th day after irradiation again. Such changes were greater in the single irradiated group than in the fractionated irradiated group. 2. The reaction to PAS staining on glandular cell was decreased on the 1st and the 3rd day after irradiation, and recovered on the 7th day after irradiation. The reaction was decreased on the 14th day after irradiation again, and recovered on the 28th day after irradiation. Changes were more apparent in the single irradiated group. 3. In the scanning electron microscopic examination, early changes of microvasculature were decreased capillary density, dilation of conduits and meandering. Increased capillary dentsity or anastomosis due to vascular reproduction and smooth curved running were observed on the 7th and 14th day after irradiation. Decreased capillary and smooth running tendency were observed on the 28th day after irradiation again. Such changes were greater in the single irradiated group than in the fractionated irradiated group.

• Journal of Korean Foot and Ankle Society
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• v.13 no.1
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• pp.46-49
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• 2009

Purpose: The purpose of this study is to find out the normal angles of forefoot for diagnosis of bunionette deformity in Korea. This would be helpful as it would provide a basic angular measurement of bunionette deformity that indicates the need for operation. Materials and Methods: Within a period of four months from January 2007 to April 2007. We have established 300 males and 600 feet without trauma history of foot. The source to image distance is 40 inches and erect weight bearing radiographs are obtained in anteroposterior and lateral projections. The significant angular measurements that define a bunionette deformity are the fourth-fifth intermetatarsal angle, the fifth metatarsophalangeal angle Results: The mean age was 21 years(19-22 years) old. The mean $4^{th}-5^{th}$ intermetatarsal angle was $9.4{\pm}4.7^{\circ}$, the mean $5^{th}$ metatarsophalangeal angle was $7.9{\pm}9.2^{\circ}$. Conclusion: We can consider over the $14.1^{\circ}$ on the $4^{th}-5^{th}$ intermetatarsal angle and over $17.1^{\circ}$ on the $5^{th}$ metatarsophalangeal angle as an operational indication.

• Journal of the Korean Society of Food Science and Nutrition
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• v.27 no.4
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• pp.698-704
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• 1998

This study was carried out to investigate the effects of diet of Korean safflower(Carthamus tinctorious L.) seed powder on bone tissue during the recovery of rib-fracture in rats. Male Sprague-Dawley rats of 10 weeks old, weighing 370$\pm$5g, were divided into two groups including the control group(C group, AIN-76 semipurified diet) and safflower seed group(S group, AIN-76 semipurified diet+10% safflower seed powder) and were fed experimental diets for 12 days after adaptation period. After this period, the 9th right rib was fractured surgically and sham-operation was also performed. Rats were fed with experimental diets for up to 30 more days after rib-fracture. The degree of bone repair was evaluated during the recovery period at the 8th, 11th, 16th, 21st, 30th days after the surgical operation by microscopic observation of the fractured rib tissue. In callus formation, the portion of hyaline cartilage was noticably higher in S group than C group. The intracatilagenous ossification was observed at the 8th day in S group, but at 11th day in C group. The intramembranous ossification in callus was widely found over the 8th day to the 11th day in S group, but it was shown over the 11th day to the 16th day in C group. Bone resorption was also occured more rapidly in S group as indicated by large numbers of osteoclasts observed. At the 30th day, most of trabecular bones were disappeared in S group, whereas still shwon in C group over wide ranges of fractured ribs. These results imply that the supplementation of Korean safflower seed powder influences in the recovery of bone fracture by accelerating the process of bone repair.

• Korean Journal of Childcare and Education
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• v.13 no.2
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• pp.21-37
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• 2017

Objective: The current study aimed at examining the mediation effects of children's self-esteem and self-control in learning between perceived academic achievement at $4^{th}$ grade and $6^{th}$ grade. This article proposes that perceived academic achievement boosts self-esteem and self-control in learning and both in turn, influence subsequent perceived academic achievement. We especially attempted to empirically prove that a serial multiple mediation of self-esteem and self-control in learning between the perceived academic achievement at two time points exists. Methods: We analyzed the longitudinal data of 1,881 children from the $4^{th}$ to the $6^{th}$ wave data of the '2010 Korea Children and Youth Panel Survey (KCYPS)' by means of a Hayes's PROCESS(2012) program. Results: The results revealed that perceived academic achievement at $4^{th}$ grade influenced children's self-esteem and self-control in learning at $5^{th}$ grade. Children' self-esteem and self-control in learning subsequently predicted perceived academic achievement at $6^{th}$ grade. Children's self-esteem significantly predicted self-control in learning supporting the hypothesis of serial multiple mediation. Conclusion/Implications: In conclusion, children's self-esteem and self-control in learning behaviors both mediated the association between perceived academic achievement at $4^{th}$ grade and at $6^{th}$ grade. The findings imply the importance of consideration of both psychosocial and behavioral aspects in understanding the academic performance during childhood.