• Journal of Digital Convergence
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• v.14 no.1
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• pp.453-463
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• 2016

This study examined the relationship among dropout, organizational trust, and intention to transfer in the department affiliated with Physical Education. Data were collected from 480 students in the department affiliated with Physical Education from 6 institutions of a 4-year university located in Seoul, Gyeonggi-do, Incheon, and ChungChong-do. For the research model analysis, a structural equation model and bootstrapping were conducted. Results indicated that the academic domain, the social domain, and the environmental domain of dropout had a positive effect on organizational trust. But the only the academic domain in the relationship between dropout and intention to transfer affected intention to transfer positively. The social domain and the environmental domain were not statistically significant on intention to transfer. Moreover, organizational trust had a positive effect on intention to transfer. Finally, organizational trust partially mediated the path between the academic domain and intention to transfer. It fully mediated the paths between the social domain and the environmental domain and intention to transfer.

• Journal of the Korean Society of Radiology
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• v.83 no.5
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• pp.1121-1127
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• 2022

Endometriosis-related symptoms are believed to be alleviated during pregnancy. However, pregnancy complications, such as pseudoaneurysm of the uterine artery, rupture of ovarian or uterine vessels, and intraabdominal bleeding from decidualized deep infiltrating endometriosis (DIE) lesion have been rarely reported. Owing to the potential risk of rupture and resultant life-threatening complications, proper diagnosis and close monitoring of decidualized endometriotic lesion are very important despite its low relative risk. Till date, massive vaginal bleeding from decidualized rectovaginal DIE during pregnancy has not been in English literatures. Here, we present the first case of spontaneous massive vaginal bleeding due to decidualized rectovaginal DIE that occurred in the late third trimester of pregnancy.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.2
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• pp.119-129
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• 2008

Objective: The purpose of this study was to quantify decidual $CD56^+$ and $CD16^+$ NK cell subtype population and to evaluate the correlation between decidual NK cell expression and peripheral $CD56^+$ NK cell expression in women with a history of recurrent abortion and increased peripheral NK cells. Methods: Twenty-nine women with recurrent abortion and elevated peripheral $CD56^+$ NK cell percentage who had chromosomally normal conceptus were included in this study. Thirty-two women with recurrent abortion who had chromosomally abnormal conceptus were used as controls. Distribution of $CD56^+$ and $CD16^+$ NK cells in decidual tissues including implantation sites was examined by immunohistochemical staining. The degree of immunohistochemical staining was interpreted by score and percentage. Results: There was a significant difference in decidual $CD56^+$ NK cell score ($43.6{\pm}24.5$ vs. $23.9{\pm}16.3$ P =0.001) and $CD56^+$ NK cell percentage ($42.1{\pm}11.7$ vs. $33.9{\pm}15.8$ P =0.027) between increased peripheral NK cell group and control group. However, there was no statistically significant difference in decidual $CD16^+$ NK cell score ($18.7{\pm}9.5$ vs. $13.2{\pm}39.4$ P =0.108) and $CD16^+$ NK cell percentage ($24.7{\pm}5.9$ vs. $23.4{\pm}11.7$ P =0.599). There was no significant correlation between decidual NK cell score and peripheral NK cell percentage in increase peripheral NK cell group (peripheral $CD56^+$ NK cell percentage vs. decidual $CD56^+$ NK cell score, r=-0.016, P =0.932, peripheral $CD16^+$ NK cell percentage vs. decidual $CD16^+$ NK cell score, r=0.008, P =0.968). Conclusion: This study shows that $CD56^+$ decidual NK cells are increased in decidua of women exhibiting a history of recurrent abortion with increased $CD56^+$ peripheral NK cell. There was no significant correlation between decidual and peripheral NK cell increment in increase peripheral NK cell group. This study suggests the possibility that decidual NK cells may play an important role in the immune mechanism of recurrent abortion.

• The Journal of the Korean dental association
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• v.8 no.3
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• pp.279-282
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• 1970

구강점막상피는 여러 가지의 외적 자극을 받게 되는데,특히 치과보철용재료인 금속,인공수지 등으로 조제된 총의치,국부의치를 사용하는 사람들의 구강상피의 변화를 탈락세포의 각화상태를 관찰함으로서, 국소적인,기계적화학적인 자극이 점막상피에 어떤 영향을 미치며, 그것이 병적 진행 여부를 추구하였다. 이과 같이, 끼웠다 뺏다 하는 의치가 구강상피조직에 미치는 영향에 대해서는 많은 학자들이 연구해 왔다. 그리고 그들 대부분의 학자들이 비고정의치의 기능적인 작용이 악골에도 크게 자극하지만,그 보다도 점막상피에 더 많은 영향을 미치게 한다고 했다. 본인은 이러한 것을 Pap.씨법에 의하여 구강탈락세포를 관찰함으로서, 의치에 의하여 구강점막상피가 정상적인 각화과정에 장해를 받고 있는 것을 인정하게 했다. 즉 의치에 의하여 피복되어 있는 상피(접착점막)에는 정상적인 각화현상을 볼 수 없고,다만 parakeratose 로 이행되는 것을 관찰하게 되었다. 이러한 상피의parakeratose 현상은 의치에 의한 물리적인 작용(교합압)도 그 이유의 하나이겠지만,의치를 조제하는 재료,즉 금속인공수지의 화학적인 자극에 의히여 상피각화과정에 장해를 주어,의치사용자의 구강상피가 parakeratose 과정을 취하는 것을 알게 하였다. 이러한 것은 또한 의치의 교합압을 가장 많이 받는 경구개와 하악치조돌기점막상피의 각화도가 타부위에 비하여 심한 것으로 보아서도 증명된다.

• Journal of the Korean Society of Propulsion Engineers
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• v.10 no.4
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• pp.47-53
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• 2006

In this paper, the thermal insulator structure of a real rocket which is fabricated in a way that laminated composite rings are connected in series is analyzed using 3-dimensional axisymmetric finite element models. Simulation of cowl zone using a real operating conditions provides that the stress distribution in the laminated composite ring is largely influenced by ply-angles, axial dimensions, and boundary conditions. Notably the plylift that is the precursor to the wedge-out occurs in the ring-to-ring bonding region. It is hypothesized that after the plylift the wedge is dropped out due to the shear stresses in the ply-angle direction and axial compressive stresses.

• The korean journal of orthodontics
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• v.26 no.3
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• pp.317-324
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• 1996

This study was conducted to evaluate the tensile bond strength of three commercially available glass ionomer cements as orthodontic bracket adhesives. 120 premolars extracted for orthodontic treatment were prepared for bonding and standard edgewise brackets were bonded with Shofu Glaslonomer Cement (Shofu Co., U.S.A.), GC Fuji ItGC Co., Japan), KETAC-CEM(ESPE Co., West Germany) with different P/L ratio. The tensile bond strength was tested by Instron testing device after 24hours and 3months from bonding. After debracketing, bracket bases were examined to determine the failure sites. The results of this study were as follows: 1. KETAC CEM showed the highest bond strength other than measurement after 24 hours and at its original P/L ratio, and seemed to have clinically a proper bond strength. It seemed, however, that both Shofu Giaslonomer Cement and GC Fuji I had an inappropriate bond strength. 2. The incorporation of additional powder into the mixture improved the tensile bond strength. 3. Prolonged storage time improved the tensile bond strength. 4. Of the failure, failure occured at the tooth-adhesive interface(54.2%) was the most common type. The second type of failure(36.7%) was combination type, where part of the adhesive remained on the tooth and part on the bracket. And the last type of failure(9.1%) occured at the adhesive-bracket interface.

• Clinical and Experimental Reproductive Medicine
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• v.34 no.4
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• pp.275-283
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• 2007

Objective: This study was performed to investigate the expressions of endometriosis related genes in shed endometrial tissues from menstrual blood of patients with or without endometriosis. Methods: The shed endometrial tissues were collected on 2$^{nd}$ or 3$^{rd}$ day of menstrual cycle with Wallace catheter in patients with endometriosis (n=16) and without endometriosis (n=26). The mRNA expressions of twelve kinds of endometriosis related genes were compared between two groups using semi-quantitative RT-PCR. Results: The collected shed endometrium was confirmed by histological observation. Expressions of telomerase, c-kit and aromatase mRNA were not detected by RT-PCR in shed endometrial tissues. The mRNA expressions of apoptosis related genes (fas, fas ligand, bcl-2, bax), stem cell factor, estrogen receptor-$\alpha$/$\alpha$, endometriosis protein-I and secretory leukocyte protease inhibitor gene were similar between shed endometrial tissues with endometriosis and without endometriosis. Conclusion: We could not find the difference of mRNA expressions of tested endometriosis related genes between shed endometrial tissues with or without endometriosis by semi-quantitative RT-PCR analysis. It may be related to the dynamical changes of gene expressions in the endometrium with menstrual cycle.

• Korean Journal of Construction Engineering and Management
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• v.23 no.1
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• pp.46-53
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• 2022

The railway platform is an important facility closely related to the safety of passengers, trains, and images of railway facilities, and requires thorough facility management. However, the problem that the finishing material (plastering mortar) for the joint finishing of dissimilar materials (concrete+granite) falls off in the direction of the track at the platform podium is occurring multiple times across the country. Since these problems threaten the safety of train operation and the safety of passengers, immediate and continuous management is required. This study tried to derive improvement plans through the analysis of the drop-off problem of finishing materials occurring at the platform podium. The status of missing finishing materials for the platform podiums of about 200 railway stations and the related design and construction standards of the Korea National Railway were investigated. After that, the cause of the drop-off of the finishing material was analyzed, and as a result, it was found that the main cause was the boundary between the roadbed and the architectural process that occurred during construction. Subsequently, in connection with the derived causes and design, construction standards, (1) improvement of finishing materials or construction methods, (2) design of finishing materials that are easy to adjust height, (3) design of separate finishing methods, (4) improvement methods and durability were suggested.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.699-716
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• 1998

This study was designed to evaluate the expression of non-collagenous protein in periodontal tissue during the experimental movement of rat incisors, by LSAB(labelled streptavidine biotin) immunohistochemical staining for osteonectin and osteocalcin. Twenty seven Sprague-Dawley rats were divided into a control group(3 rats) and 6 experimental groups(24 rats) where 75g of force was applied from helical springs across the maxillary incisors. Rats of experimental groups were sacrificed at 12 hours, 1, 4, 7, 14 and 28 days after force application, respectively. And the tissues of a control group and experimental groups were studied immunohistochemically and histologically. The results were as follows : 1. Until 28 days after force application, periodontal fibers had been strectched on tension side and compressed in pressure side of all the experimental groups, and the arrangement of periodontal fibers had not been recovered yet. 2. The expression of osteonectin in control group was rare in dentin, cementum and osteocyte, and was mild in odontoblasts and matrix of alveolar bone. 3. The expression of osteocalcin in control group was negative in gingiva, osteoblasts, osteocyte and cementum, and was rare in predentin, capillaries in pulp and periodontal ligament and the matrix of alveolar bone. 4. There was no difference in the expression of osteocalcin or osteonectin in dentin, cementum, pulp, odontoblasts, between of control and of experimental groups. 5. The expression of osteonectin in intermaxillary suture got the peak in 7-day and was declined after 14-day. The expression of osteocalcin remained in a same degree since it became mild in 14-day. 6. The expression of osteonectin in pressure side of periodontal ligament of experimental group was rare, which was similar to control group. But in tension side, it was increased until 14-day aftrer which it was declined. 7. The expression of osteocalcin in periodntal ligament was rare in 12-hour to 14-day, but became severe in 28-day, which was greater in tension side than in pressure side, and in the periodontal fiber next to alveolar bone than to tooth surface. 8. The expression of osteocalcin in alveolar bone was rare until 14-day in pressure side, but became moderate in 28-day. The expression of osteonectin was increased from 7-day by time dependency, which was greater in tension side than in pressure side.

• Clinical and Experimental Reproductive Medicine
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• v.36 no.3
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• pp.199-207
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• 2009

Objectives: The purpose of this study was to compare the decidual NK cell populations between increased pre-conceptional peripheral NK cell population and normal pre-conceptional peripheral NK cell population in women with a history of recurrent abortion. Methods: Fourteen women with history of recurrent abortion and elevated pre-conceptional peripheral NK cell, above 15% of peripheral lymphocyte population were included in this study. As a control, twelve women with history of recurrent abortion and their peripheral NK cell percentage showed below 15% were included. Distribution of $CD56^+$ and $CD16^+$ NK cells in paraffin embedded decidual tissues including implantation sites were examined by immunohistochemical staining using anti-CD56, 16 monoclonal antibodies. After immuohistochemical staining, the numbers of decidual NK cells were counted and compared these results between study and control groups. Results: There was significant difference in decidual $CD56^+$ NK cell count ($170.1{\pm}132.1$ vs. $68.3{\pm}66.1$, p=0.02) between increased peripheral $CD56^+$ NK cell group and control group. But, there showed no statistically significant correlation between decidual $CD56^+$ NK cell count and peripheral $CD56^+$ NK cell percentage (r=0.229, p=0.261). Also there was no statistically difference decidual $CD16^+$ NK cell count between study and control group ($25.70{\pm}11.72$ vs. $31.17{\pm}22.67$), and no correlation between decidual $CD16^+$ NK cell and peripheral $CD16^+$ NK cell percentage (r=-1.40, p=0.535). Conclusions: This study shows that decidual $CD56^+$ NK cell are significantly increased in decidua of women exhibiting a history of recurrent abortion with increased $CD56^+$ peripheral NK cell. This study suggests that the percentage of peripheral NK cell reflect the expression of decidual NK cell. Consequently, pre-conceptional peripheral blood NK cell population can be the useful marker for detecting the risk of subsequent miscarriage.