• Fire Science and Engineering
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• v.23 no.5
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• pp.196-205
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• 2009

Electric mosquito repellent mats can be ignited by damage of cables, partial disconnection, overload. tracking and so on. In this study, we examined the structure of mosquito repellent mat, positive temperature coefficient(PTC) thermistor, used for heating element and phenomenological characteristics of remains, obtained on the scene of fires. After reappearance ignition test of PTC thermistors, we did comparison analysis them. And we could confine that the feature of heating plate and the shape of bursting were same.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.28 no.12
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• pp.843-846
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• 2015

In this paper, the failure mechanism of PTC heater were examined closely by failure analysis and based on it, accelerated life test were conducted. Finally, life distribution and acceleration model were established. The failure mechanism of PTC heater such as crack, increase of resistance due to heating were identified. Two acceleration factors such as temperature, humidity were chosen with two levels each and accelerated life test were done. Life distribution were identified as Weibull distribution with shape parameter 5.4 and Temperature-Humidity model was fitted as an acceleration model.

• Bulletin of the Korean Chemical Society
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• v.22 no.9
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• pp.958-962
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• 2001

The chiral amine auxiliary mediated stereoselective alkylation reactions of glycinamides 1-6 and 15-17 using phase transfer catalyst (PTC) for liquid-solid extraction are described. The secondary N-(diphenylmethylene) glycinamides 1, 2 and 3 give better selectivities and yields than tertiary N-(diphenylmethylene) glycinamides 4, 5 and 6. Alkylation of the glycinamide 1 and 2 using 18-Crown-6 as a PTC in toluene at $-40^{\circ}C$ gives best selectivities and yields. Alkylations of N-(4-chlorophenylmethylene)glycinamides 15, 16 and 17 under same PTC conditions give $\alpha$, $\alpha-disubstituted$ amino acid derivatives 18, 19 and 20 with low diastereoselectivities.

• Proceedings of the Korean Ceranic Society Conference
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• 2003.10a
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• pp.105.1-105
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• 2003

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.152-152
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• 2002

• Korean Journal of Head & Neck Oncology
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• v.26 no.2
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• pp.183-186
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• 2010

Purpose : Papillary thyroid carcinoma (PTC) is known for malignant tumor which has a favorable prognosis and long-term survival. Although the prognosis for patients with PTC is generally good, PTC tends to have highly metastatic property. The purpose of this study was to analyze the central compartment lymph node in papillary thyroid cancer with no lymph node metastasis clinically and to assess the significance of prophylactic node dissection. Methods : A retrospective review was carried out in 394 patients with PTC who underwent surgery for the period from January 2004 to December 2006. The positive rate of the lymph node metastasis was analyzed. The relations between the central compartment lymph nodes and the patients' age, gender, tumor size, exrathyroidal extension(ETE), multifocality, and bilaterality were comparatively analyzed in PTC patients with preoperative no lymph node metastasis. Results : The enrolled patients were 40 male and 354 female cases. The 118 cases of them were found to have cervical lymph node metastasis. The mean age was 46 years(range, 15-77years). Tumor size(p=0.000), ETE(p=0.001), multifocality(p=0.014), and bilaterality(p=0.001) were significantly related factors for cervical lymph node metastasis clinically in papillary thyroid cancer. However, age and gender were not significantly related with lymph node metastasis. Conclusion : Although no lymph node metastasis clinically, prophylactic neck node dissection can be performed to avoid risks of local recurrence and reoperation in the light of PTC nature. The pathological status and high positive rate of central compartment lymph node relate to tumor size and extrathyroidal extension. Close surveillance for nodal status is required in follow-up.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.1
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• pp.31-37
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• 2013

Background: Throughout Indonesia, thyroid cancer is one of the ten commonest malignancies, with papillary thyroid carcinoma (PTC) in our hospital accounting for about 60% of all thyroid nodules. Although fine needle aspiration biopsy (FNAB) is the most reliable diagnostic tool, some nodules are diagnosed as indeterminate and second surgery is common for PTC. The aim of this study was to establish the diagnostic value and feasibility of testing the BRAF T1799A mutation on FNA specimens for improving PTC diagnosis. Materials and Methods: This prospective study enrolled 95 patients with thyroid nodules and future surgery planned. Results of mutational status were compared with surgical pathology diagnosis. Results: Of the 70 cases included in the final analysis, 62.8% were PTC and the prevalence of BRAF mutation was 38.6%. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) for BRAF mutation analysis were 36%, 100%, 100% and 48%, respectively. With other data findings, nodules with "onset less than 5 year" and "hard consistency" were proven as diagnostic determinants for BRAF mutation with a probability of 62.5%. This mutation was also a significant risk factor for extra-capsular extension. Conclusions: Molecular analysis of the BRAF T1799A mutation in FNAB specimens has high specificity and positive predictive value for PTC. It could be used in the selective patients with clinical characteristics to facilitate PTC diagnosis and for guidance regarding extent of thyroidectomy.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.17
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• pp.7449-7452
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• 2014

Background: The purpose of this study was to investigate the correlation of contrast-enhanced ultrasonographic (CEUS) features with microvessel density (MVD) in papillary thyroid carcinomas (PTCs). Materials and Methods: Contrast-enhanced ultrasonography (CEUS) was performed in 62 patients (17 men and 45 women) with PTC. Tomtec software was applied to analyze the time intensity curve of CEUS. Immunohistochemistry was performed to evaluate the level of MVD in papillary thyroid carcinoma. Then the relationship between quantitative feature and the level of MVD was analyzed using SPSS 16.0 software. Results: The mean peak intensity of PTC tissues was lower than that of peripheral thyroid parenchyma ($61.9{\pm}11.8%$ vs 100%, p<0.05). The MVDs of CD34 and CD31 antibodies staining were $38.0{\pm}6.1$ and $37.9{\pm}5.1$ respectively in 62 PTC samples. A significantly positive correlation was observed between peak intensity and MVD in PTC tissues ($P_{CD34}$<0.01, $r_{CD34}$=0.838, $P_{CD31}$<0.01, $r_{CD31}$=0.837). Conclusions: The peak intensity in CEUS could reflect the MVD in PTC tissues. Therefore, quantification of CEUS seems to be helpful for assessment of MVD in PTC tissues.

• Journal of Yeungnam Medical Science
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• v.32 no.2
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• pp.138-142
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• 2015

L-thyroxine (LT4) withdrawal prior to radioactive iodine (RAI) ablation therapy is a commonly used method for successful treatment of patients with papillary thyroid cancer (PTC). However, a prolonged period of hypothyroidism induced by LT4 withdrawal is sometimes associated with impaired quality of life and cardiopulmonary dysfunction in PTC patients. Furthermore, LT4 withdrawal may have a trophic effect on residual cancer by means of increased thyrotropin. We report on 2 cases of metastatic PTC patients with malignant pleural effusion (MPE) whose disease showed rapid worsening after LT4 withdrawal and RAI therapy. The first case is a 65-year-old woman who had PTC with multiple distant metastases and MPE. During LT4 withdrawal for RAI therapy, MPE showed rapid worsening, and the patient required repetitive therapeutic thoracentesis. The second case is a 49-year-old woman with PTC who underwent 3 additional operations for cancer recurrence in the neck lymph nodes and 6 times of RAI treatments. While preparing for the $7^{th}$ RAI treatment by withdrawing LT4, she developed MPE which became progressively aggravated after RAI therapy. Both patients experienced increased pleural effusion during the LT4 withdrawal period and a rise in the thyroglobulin level was observed after RAI therapy. MPE was not controlled with therapeutic thoracentesis and pleurodesis. Eventually, both patients died of rapid disease progression after RAI therapy. In summary, LT4 withdrawal may have an adverse effect on metastatic PTC patients, particularly those with MPE.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.2
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• pp.855-860
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• 2014

Background: The purpose of this study was to assess the relationship between different sonographic features of papillary thyroid carcinoma (PTC) on high-frequency ultrasound and cervical lymph node metastasis (CLNM). Materials and Methods: We enrolled 548 patients who underwent initial surgery for PTC between May 2011 and December 2012 in our hospital at diagnosis. The sonographic features of 513 PTC nodules in 513 eligible patients, who had single PTC nodules in their thyroid glands, were retrospectively investigated. All patients with a suspect malignant nodule (d<0.5cm) among multiple nodules were initially diagnosed by fine-needle aspiration biopsy (FNAB) to ascertain if the suspect nodule was PTC. The final diagnosis of all the thyroid nodules and existence of CLNM were based on postoperative pathology. Patients were divided into two groups: a positive group with CLNM (224 nodules) and a negative group without CLNM (289 nodules). The following factors were investigated: gender, age, echogenicity, echotexture, size, shape, location, margin, contour, calcification morphology, distance between the nodule and pre- or post-border of the thyroid capsule, vascularity and the differences between the two groups. Results: Correlation analysis showed that shorter distances between the nodule and pre- or postborder of thyroid capsule resulted in greater risk of CLNM (Spearman correlation coefficient=-0.22, p<0.0001). The significant factors in multivariate analysis were age<45yrs, larger size (d>1cm), "wider than tall" shape, extrathyroid extension and mixed flow (internal and peripheral) (p<0.05, OR=0.406, 2.093, 0.461, 1.610, 1.322). Conclusions: Significant sonographic features of PTC nodules in preoperative high-frequency ultrasound are crucial for predicting CLNM.