• Transactions of the Korean Society of Mechanical Engineers A
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• v.38 no.6
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• pp.637-647
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• 2014

In pressurized water reactors, the upper head of the reactor pressure vessel (RPV) contains numerous control rod drive mechanism (CRDM) nozzles. These nozzles are fabricated by welding after being inserted into the RPV head with a room temperature shrink fit. The tensile residual stresses caused by this welding are a major factor in primary water stress corrosion cracking (PWSCC). Over the last 15 years, the incidences of cracking in alloy 600 CRDM nozzles have increased significantly. These cracks are caused by PWSCC and have been shown to be driven by the welding residual stresses and operational stresses in the weld region. Various measures are being sought to overcome these problems. The defects resulting from the welding process are often the cause of PWSCC acceleration. Therefore, any weld defects found in the RPV manufacturing process are immediately repaired by repair welding. Detailed finite-element simulations for the Korea Nuclear Reactor Pressure Vessel were conducted in order to predict the magnitudes of the repair weld residual stresses in the tube materials.

• Archives of Craniofacial Surgery
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• v.9 no.1
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• pp.1-7
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• 2008

Osteomas are most often located in the femur, tibia, humerus, spine, and talus. They are rare in the skull. Osteomas in the head and neck regions are benign bone neoplasms usually found in the frontoethmoid area. The developmental theory postulates that osteomas develop at the sites of fusion of tissues different embryological origin such as occur at the junction of the embryonic cartilaginous frontal and ethmoid bones. Trauma and infection have also been implicated as causative factors, but many patients with osteoma deny any preceding history of these. Osteomas are usually produce symptoms primary to cosmetic problems and secondary to pressure on adjacent structures. The objects of this study are from a 5-year period of April of 2002 to April of 2007, consisting of 48 male patients and 52 female. There were 33 cases of frontal bone osteomas, 5 cases of madibular bone osteomas, 5 cases of occipital bone osteomas, 6 cases of symptomatic paranasal sinus osteomas, 48 cases of asymptomatic paranasal sinus osteomas, and 3 cases of mastoid osteomas. We reviewed medical records of patients to find out their presentations, diagnostic considerations, therapeutic options, and outcomes. Patients were followed up six months postoperatively on the average. The authors experienced 48 cases of osteoma in the head and neck lesion, which were removed via direct approach or endoscopic approach. The 100 cases who came to the hospital with or without symptoms after diagnosis healed completely without sequelae. During the follow-up periods, excellent functional and cosmetic results were observed with an inconspicuous scar. There was no specific complications related to this procedure. Results of surgery in most cases were satisfied. We discussed the surgical procedure and the characteristics of the osteomas, and we report several cases with the review of literatures.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.17
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• pp.7627-7632
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• 2015

Background: The present study was conducted to evaluate the technical feasibility, safety and adequacy of surgical margins with salvage transoral robotic surgery (TORS) for recurrent or residual head and neck squamous cell carcinoma patients. Materials and Methods: Thirty patients who underwent salvage TORS using the 'DaVinci' robot were enrolled in the study and data related to their surgical time, complications and functional outcome were recorded. Results: The feasibility of salvage TORS in our study was observed to be 100%. Positive margins were encountered in only 6.7% of patients. Mean blood loss was 23.3 ml with no patient requiring blood transfusion. Postoperative complications in the form of primary haemorrhage requiring active surgical intervention occurred in 13.3%. Oral feeding could be started as early as the 3rd postoperative day in a few patients, with nasogastric tubes being removed on the 12th postoperative day. Long term gastrostomy tube dependency was seen in 10% cases. Median survival of patients was 19 months. Conclusions: Salvage TORS is a safe, effective and feasible option in the management of treatment failure cases. It offers an alternative surgical approach with unexpected benefits in terms of tracheostomy tube use, Ryle's tube and gastrostomy dependence.

• Research in Community and Public Health Nursing
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• v.19 no.1
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• pp.36-45
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• 2008

Purpose: This study was to estimate the prevalence of dementia in order to estimate the associations of dementia with its risk factors in the community elderly. Methods: The multistage random cluster sampling method was used to select the subjects. The response rate was 94.3%. For the 1st stage screening survey, the Korean-version Mini-Mental State Examination (K-MMSE) and the Bathel Index of activities of daily living (ADL) and instrumental activities of daily living (IADL) were used as primary screening tools. At the 2nd stage. diagnoses were confirmed according to the Clinical Dementia Rating Scale (CBR) and Computer Tomogram (CT). Results: Age-sex adjusted prevalence (%) [95% CI] of dementia was 6.25% [4.47-7.83] (male 4.21% [2.40-6.02]; female 8.28% [5.71-10.85]). Four statistically significant risk factors of the dementia were identified: age 70-74 (OR=1.367), age 75-79 (OR=1.712), age 80-84 (OR=2.465), age 85 over (OR=7.363) illiteracy (OR=3.827); unconsciousness after head injury (OR=3.383), and no exercise (OR=2.188). Hosmer and Lemeshow goodness-of-fit index of dementia risk model was E (legit of dementia)= -4.337+$0.312^*Age(70{\sim}74)+0.538^*Age(75{\sim}79)+0.902^*Age(80{\sim}84)+1.996^*Age$(85over)+$1.342^*$Illiteracy+$1.219^*$Unconsciousness after head trauma+$0.783^*$No exercise. We confirmed that the overall prevalence of dementia in adults aged 65 and older was 94.3%. The risk factors of dementia were explained by age, illiteracy unconsciousness after head trauma and no exercise. Conclusion: These data have been used to estimate the incidence of dementia in elderly community population and to manage the possible role of risk factors as predictors of dementia.

• Parasites, Hosts and Diseases
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• v.49 no.1
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• pp.95-98
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• 2011

Head louse infestation (HLI) is one of the most frequently occurring parasitic diseases in children. This study was conducted to investigate the socioeconomic and personal factors influencing HLI in the Republic of Korea. A total of 2,210 questionnaires about various factors related to HLI were obtained from children in 17 primary schools throughout the country. The rate of HLI was significantly lower in children who lived together with mother or in a family where both parents worked. In addition, HLI was lower in children whose fathers or mothers were public officers or teachers. However, HLI was higher in children who had small families and washed their hair less often. Education levels of parents and the number of children in family were not significant. Improvement of socioeconomic factors and personal hygiene will be helpful for reducing HLI.

• Journal of the Korean Society of Laryngology, Phoniatrics and Logopedics
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• v.19 no.1
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• pp.43-46
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• 2008

Background and Objectives : Clinical suspicion and appropriate diagnostic procedures are essential for the timely management of extrapulmonary type of mycobacterial disease. In the hope of suggesting a suitable guideline for the early diagnosis of laryngeal tuberculosis, the authors reviewed their clinical pathways and the characteristics of patients with laryngeal tuberculosis who were managed in the recent 10 years at a single tertiary referral hospital, Samsung Medical Center. Subjects and Method : Retrospective chart review was performed for the 25 adult patients with laryngeal tuberculosis. Among 25 cases, 12 were pathologically confirmed by laryngeal biopsy and the other 13 were clinically diagnosed by cumulative clinical information; definite laryngitis on laryngoscopy, positive AFB (acid fast bacillus) smear/culture or active pulmonary tuberculosis on chest X-ray, and substantial response to anti-tuberculosis medication. Results : Chest X-ray revealed active pulmonary tuberculosis in 72% of patients (N=18/25). Sputum AFB smear/culture was positive in 95% of all tested patients (N=21/22) and in 100% of the tested patients who have stable or no evidence of pulmonary tuberculosis (N=5/5). All patients except one who had coexisting laryngeal malignancy showed considerable improvement in their subjective symptoms and laryngeal findings within the first 2 months of anti-tuberculosis medications and they achieved complete response on subsequent sputum studies, chest X-ray and laryngeal findings after $7.0{\pm}2.3$ months of the medications. Conclusion : We suggest that chest X-ray and sputum AFB smear/culture to be the first step of work-up for the patients having laryngeal tuberculosis in suspicion since laryngeal tuberculosis is largely associated with active pulmonary tuberculosis and/or sputum AFB study offers high yield even in case of primary laryngeal tuberculosis. However laryngeal biopsy must be considered in case showing unsatisfactory response to the anti-tuberculosis medication for more than 2 months.

• Radiation Oncology Journal
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• v.30 no.1
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• pp.36-42
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• 2012

Purpose: To evaluate the radial displacement of clinical target volume in the patients with node negative head and neck (H&N) cancer and to quantify the relative positional changes compared to that of normal healthy volunteers. Materials and Methods: Three node-negative H&N cancer patients and five healthy volunteers were enrolled in this study. For setup accuracy, neck thermoplastic masks and laser alignment were used in each of the acquired computed tomography (CT) images. Both groups had total three sequential CT images in every two weeks. The lymph node (LN) level of the neck was delineated based on the Radiation Therapy Oncology Group (RTOG) consensus guideline by one physician. We use the second cervical vertebra body as a reference point to match each CT image set. Each of the sequential CT images and delineated neck LN levels were fused with the primary image, then maximal radial displacement was measured at 1.5 cm intervals from skull base (SB) to caudal margin of LN level V, and the volume differences at each node level were quantified. Results: The mean radial displacements were 2.26 (${\pm}1.03$) mm in the control group and 3.05 (${\pm}1.97$) in the H&N cancer patients. There was a statistically significant difference between the groups in terms of the mean radial displacement (p = 0.03). In addition, the mean radial displacement increased with the distance from SB. As for the mean volume differences, there was no statistical significance between the two groups. Conclusion: This study suggests that a more generous radial margin should be applied to the lower part of the neck LN for better clinical target coverage and dose delivery.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.10
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• pp.1235-1239
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• 2012

Primary water stress corrosion cracking (PWSCC) has been observed around the weld region of control rod drive mechanism (CRDM) nozzles in nuclear power plants overseas. The weld has a J-shaped groove and it connects the CRDM nozzle with the reactor vessel upper head (RVUH). It is a dissimilar metal weld (DMW), because the CRDM is made of alloy 600 and the RVUH is made of carbon steel. In this study, finite element analysis (FEA) was performed to estimate the stress condition around the weld region. Generally, it is known that a high tensile region is more susceptible to PWSCC. FEA was performed as for the condition of welding, hydrostatic test and normal operation successively to observe how the residual stress changes due to plant condition. The FEA results show that a high tensile stress region is formed around the weld starting point on the inner surface and around the weld stop point on the outer surface.

• Korean Journal of Head & Neck Oncology
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• v.10 no.2
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• pp.178-184
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• 1994

Laryngeal cancer is one of the most frequent cancers in the head and neck area. Clinical analysis was performed on 30 cases of treated $T_1$ glottic cancer patients. Early glottic cancer occured most frequently in male in their sixties and all were well or moderately well differentiated squamous cell carcinoma. Overall five year survival rate was 81.5% and there was no significant difference between stages or the differentiation of the diseases. Recurrence at the primary site, especially anterior commissure, was common, thus careful pre- and postoperative follow up evaluation is recommended.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.31 no.6
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• pp.468-473
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• 2005

Head and neck squamous cell carcinoma (HNSCC) is the sixth most common malignancy worldwide. The molecular mechanisms involved in the development and progression of these carcinomas are not well known. Abnormalities of genomic methylation patterns have been attributed a role in carcinogenesis and local de novo methylation at tumor suppressor loci was held to be involved in silencing of tumor suppressor genes. Using Ms APPCR, we previously isolated a hypermethylated fragment corresponded to the 5' end of TPEF gene from primary liver and lung cancer cells. To confirm the inactivation of TPEF gene by hypermethylation in HNSCC, we investigated correlation between methylation pattern and expression of TPEF in 10 HNSCC cell lines. In methylation analysis such as combined-bisulfite restriction analysis(COBRA) and bisulfite sequencing, only RPMI 2650 showed none methylated pattern and another 9 cell lines showed dense methylation. The TPEF gene expression level analysis using RT-PCR showed that these 9 cell lines had not or significantly low expression levels of TPEF as compared with RPMI 2650. In addition, the increase of TPEF reexpression by 5-AzaC as demethylating agent in 9 cell lines also indicated that TPEF expression was regulated by hypermethylation. These results of this study demonstrate that epigenetic silencing of TPEF gene by aberrant methylation could play an important role in HNSCC carcinogenesis.