• The Journal of Advanced Prosthodontics
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• v.7 no.3
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• pp.224-232
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• 2015

PURPOSE. The purpose of this study was to find out the effect of immediate dentin sealing (IDS) on bond strength of ceramic restoration under various thermocycling periods with DBA (dentin bonding agent system). MATERIALS AND METHODS. Fifty freshly extracted human mandibular third molars were divided into 5 groups (1 control and 4 experimental groups) of 10 teeth. We removed enamel layer of sound teeth and embedded them which will proceed to be IDS, using All Bond II. A thermocycling was applied to experimental groups for 1, 2, 7, 14 days respectively and was not applied to control group. IPS Empress II for ceramic was acid-etched with ceramic etchant (9.5% HF) and silane was applied. Each ceramic disc was bonded to specimens with Duo-link, dual curable resin cement by means of light curing for 100 seconds. After the cementation procedures, shear bond strength measurement and SEM analysis of the fractured surface were done. The data were analyzed with a one-way ANOVA and Tukey multiple comparison test (${\alpha}$=.05). RESULTS. There were no statistically significant differences between 4 experimental groups and control group, however the mean value started to decrease in group 7d, and group 14d showed the lowest mean bond strength in all groups. Also, group 7d and 14d showed distinct exposed dentin and collapsed hybrid layer was observed in SEM analysis. CONCLUSION. In the present study, it can be concluded that ceramic restorations like a laminate veneer restoration should be bonded using resin cement within one week after IDS procedure.

• Journal of the Korean Society of School Health
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• v.25 no.2
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• pp.143-146
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• 2012

Purpose: The purpose of this study was to review the academic development of school health system and projects implemented in Korea since 1945. Methods: This study analyzed and reviewed literatures to find out the process of the development of school health system and projects implemented in Korea. Results: The history of school health in Korea since 1945 could be divided into three periods according to the development of school health system and projects; countermeasure period (1945-1969), support period (1970-1999), and innovation period (2000~). The major school health system and projects were focused on the health screening and prevention, health management and support, and health promotion for each period. Conclusion: School health system in Korea has been set successfully due to school health law(1967) and school meal law(1981), and various countermeasure, support, and innovation projects had implemented during last 60 years.

• Journal of Korean Neurosurgical Society
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• v.52 no.5
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• pp.452-458
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• 2012

Objective : In the present study, we evaluated the effect, safety and radiological outcomes of cervical hybrid surgery (cervical disc prosthesis replacement at one level, and interbody fusion at the other level) on the multilevel cervical degenerative disc disease (DDD). Methods : Fifty-one patients (mean age 46.7 years) with symptomatic multilevel cervical spondylosis were treated using hybrid surgery (HS). Clinical [neck disability index (NDI) and Visual Analogue Scale (VAS) score] and radiologic outcomes [range of motion (ROM) for cervical spine, adjacent segment and arthroplasty level] were evaluated at routine postoperative intervals of 1, 6, 12, 24 months. Review of other similar studies that examined the HS in multilevel cervical DDD was performed. Results : Out of 51 patients, 41 patients received 2 level hybrid surgery and 10 patients received 3 level hybrid surgery. The NDI and VAS score were significantly decreased during the follow up periods (p<0.05). The cervical ROM was recovered at 6 and 12 month postoperatively and the mean ROM of inferior adjacent segment was significantly larger than that of superior adjacent segments after surgery. The ROM of the arthoplasty level was preserved well during the follow up periods. No surgical and device related complications were observed. Conclusion : Hybrid surgery is a safe and effective alternative to fusion for the management of multilevel cervical spondylosis.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.5
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• pp.275-280
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• 2008

A brief ischemic insult induces significant protection against subsequent massive ischemic events. The molecular mechanisms known as preconditioning (PC)-induced ischemic tolerance are not completely understood. We investigated whether kinetic changes of cyclooxygenase (COX)-2 during reperfusion time-periods after PC were related to ischemic tolerance. Rats were given PC by occlusion of middle cerebral artery (MCAO) for 10 min and sacrificed after the indicated time-periods of reperfusion (1, 2, 4, 8, 12, 18 or 24 h). In PC-treated rats, focal ischemia was induced by occlusion of MCA for 24 h and brain infarct volume was then studied to determine whether different reperfusion time influenced the damage. We report that the most significant protection against focal ischemia was obtained in rats with 8 h reperfusion after PC. Administration of indomethacin (10 mg/kg, oral) or rofecoxib (5 mg/kg, oral) 48 h prior to PC counteracted the effect of PC. Immunohistochemical analysis showed that COX-2 and HO-l protein were induced in PC-treated rat brain, which was significantly inhibited by rofecoxib. Taken together, we concluded that the kinetic changes of COX-2 expression during the reperfusion period after PC might be partly responsible for ischemic tolerance.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.34 no.4
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• pp.280-285
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• 2012

From the standpoint of general guidelines of a dentist, the following conditions should be considered before replanting a permanent tooth. The avulsed tooth should be without advanced periodontal disease. The alveolar socket should be reasonably intact in order to provide a seat for the avulsed tooth. The extra-alveolar period should be considered, i.e. periods exceeding. 2 hours are usually associated with marked root resorption. But, the above mentioned regulations are often difficult to keep in the actual situation of the medical emergency room, owing it to the delay of primary medical care in multiple trauma patients. The successful cases have been reported with minimal root resorption in the long-term periods, in spite of extra-alveolar periods of several hours and combined alveolar bone fracture. This is a case report regarding the effect of endodontic drainage in delayed replantation after a prolonged extra-alveolar period of the avulsed teeth with alveolar bone fracture.

• The Journal of Korean Physical Therapy
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• v.16 no.2
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• pp.140-155
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• 2004

The purpose of this study was to assess the effectiveness of scapular pattern of PNF on the pain level in whiplash injury patients. Pain level were assessed prior, after first, after second, after third, after fourth, and after fifth treatment. All 6 times were calculated pain level. To find out the effectiveness of scapular pattern of PNF, we were divide two groups. The one group was consisted of 25 patients that were treated with H/P electrical therapy and MFR, and the other group was consisted of 25 patients that were treated with H/P, electrical therapy, and scapular pattern of PNF. The results were as follow: 1. There were statistical significance on the pain level in MFR group during all treatment periods(p<0.05). 2. There were statistical significance on the pain level in scapular pattern of PNF group all during treatment periods(p<0.05). 3. Scapular pattern of PNF group had more statistical significance than MFR group on the pain level during all treatment periods(p<0.05). Consequently, this study suggest that scapular pattern of PNF technique has a very effectiveness to the whiplash injury patients.

• The Journal of Korean Physical Therapy
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• v.16 no.3
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• pp.125-141
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• 2004

The purpose of this study was to assess the effectiveness of myofascial release(MFR) technique and Taping therapy on the pain level in whiplash injury patients. Pain level were assessed prior treatment, after first treatment, after second treatment, after third treatment, after fourth treatment, and after fifth treatment. All 6 times were calculated pain level. To find out the effectiveness of MFR and Taping therapy, we were divide two groups. The one group was consisted of 25 patients that were treated with H/P, electrical therapy and MFR, and the other group was consisted of 25 patients that were treated with H/P, electrical therapy, and Taping therapy. The results were as follow: 1. There were statistical significance on the pain level in MFR group during all treatment periods(p<0.05). 2. There were statistical significance on the pain level in Taping group all during treatment periods(p<0.05). 3. Taping group had more statistical significance than MFR group on the pain level during all treatment periods(p<0.05). Consequently, this study suggest that Taping therapy has a very effectiveness to the whiplash injury patients.

• Industrial Engineering and Management Systems
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• v.14 no.4
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• pp.372-378
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• 2015

In labor-intensive enterprise, such as garment factory, assembly line is widely used as a manufacturing process for reducing costs and production time. However, for the sake of the various working capacity of worker, idle or delay may happen and influence the rear processes. If these unforeseeable delay happened continuously, it may influence the whole manufacturing process and a model, which is called limited-cycle model with multiple periods (LCMwMP), is assumed to evaluate the influence risk. In order to minimize the risk, the assignment of the workers is focused on. In this paper, we deal with an assembly line as LCMwMP model when two kinds of workers exist, whose efficiency is assumed to two different groups. We consider an optimization problem for finding an assignment of workers to the line that minimizes total expected risk, which is exchanged to expected cost by reset model of LCMwMP. First, reset model as a simple model of LCMwMP is introduced. Then, some hypotheses of the rules of the optimal worker assignment are proposed and some numerical experiments are researched assuming the processing time as Erlang distribution. Finally, the other rules on other certain conditions are discussed.

• Advances in environmental research
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• v.9 no.2
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• pp.123-133
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• 2020

A time series dataset was conducted to ascertain the effect of water table on the variability in and emission of CH₄ and CO₂ concentrations at a closed landfill site. An in-situ data of methane/carbon dioxide concentrations and environmental parameters were collected by means of an in-borehole gas monitor, the Gasclam (Ion Science, UK). Linear regression analysis was used to determine the strength of the correlation between ground-gas concentration and water table. The result shows CH₄ and CO₂ concentrations to be variable with strong negative correlations of approximately 0.5 each with water table over the entire monitoring period. The R² was slightly improved by considering their concentration over single periods of increasing and decreasing water table, single periods of increasing water table, and single periods of decreasing water table; their correlations increased significantly at 95% confidence level. The result revealed that fluctuations in groundwater level is the key driving force on the emission of and variability in groundgas concentration and neither barometric pressure nor temperature. This finding further validates the earlier finding that atmospheric pressure - the acclaimed major control on the variability/migration of CH₄ and CO₂ concentrations on contaminated sites, is not always so.

• Journal of Korean society of Dental Hygiene
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• v.17 no.5
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• pp.747-755
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• 2017

Objectives: The purpose of study is to investigate periodontal disease-related recognition and oral health-related behavior in orthodontic patients with fixed appliance. Methods: A self-reported questionnaire was completed by 286 orthodontic patients with fixed appliance in Gwangju, Jeonnam from September 1 to September 27, 2016. The questionnaire consisted of general characteristics (3 items), orthodontic related characteristics (3 items), knowledge of periodontal disease (3 items), and oral health-related behavior (4 items). The data were analyzed by frequency analysis, percentage and chi-square analysis using SPSS 21.0 program. Results: 62.8% had experiences of dental treatment and 67.5% had intention of involvement on incremental care program in orthodontic treatment periods. Accuracy rate of cause about periodontal disease was high in female and case of acquiring information experiences on periodontal disease (p<0.05). 67.2% performed correct toothbrushing for the management of periodontal disease in the experiences of acquiring information on periodontal disease in orthodontic treatment periods (p<0.05). The proportions of using interdental toothbrush and mouth rinsing solutions were high among those over 20 years old and students in the subjects (p<0.05). Conclusions:The accuracy rate were high in the answers about cause and management of periodontal disease in case of acquiring information experiences on periodontal disease in orthodontic treatment periods. Therefore, there is a need to further development and implementation of dental hygiene intervention program for periodontal disease care with fixed orthodontic appliances in that regard.