• The Journal of Korean Academy of Prosthodontics
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• v.52 no.2
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• pp.97-104
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• 2014

This study was aimed to compare the radiopacity of four kinds of currently available resin based implant cements using digital radiography. Materials and Methods: Four resin-based implant cements((Estemp $Implant^{TM}$ (Spident, Incheon, Korea), $Premier^{(R)}$Implant (Premier, Pennsylvania, USA), $Cem-Implant^{TM}$ (B.J.M lab, Or-yehuda, Israel), $InterCem^{TM}$ (SCI-PHARM, California, USA)) and control group (Elite Cement $100^{TM}$ (GC, Tokyo, Japan) ) were mixed and cured according to the manufacturer's instructions on the custom made split-type metal mold. A total of 150 specimens of each cement were prepared and each specimen (purity over 99%) was placed side-by-side with an aluminum step wedge for image taking with Intraoral X-ray unit (Esx, Vatech, Korea) and digital X-ray sensor (EzSensor, Vatech, Korea). For the evaluation of aluminum wedge equivalent thickness (mm Al), ImageJ 1.47 m (Wayne Rasband, National Institutes of Health, USA) and Color inspector 3D ver 2.0 (Interaktive Visualisierung von Farbraumen, Berlin, Germany) programs were used. Result: Among the 5 cements, Elite cement $100^{TM}$ (control group) showed the highest radio-opacity in all thickness. In the experimental group, $InterCem^{TM}$ had the highest radio-opacity followed by $Premier^{(R)}$ Implant $Cement^{TM}$, $Cem-Implant^{TM}$ and Estemp $Implant^{TM}$. In addition, $InterCem^{TM}$ showed radio-opacity that met the ISO No. 4049 standard in all the tested specimen thickness. Cem-Implant on 0.5 mm thickness showed radiopacity that met the ISO No. 4049 standard. Conclusion: Among the implant resin-based cements tested in the study, $Premier^{(R)}$ Implant Cement and Estemp $Implant^{TM}$ did not show appropriate radio-opacity. Only $InterCem^{TM}$ and $Cem-Implant^{TM}$ 0.5 mm specimen had the proper radiopacity and met the experiment standard.

• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.1
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• pp.132-142
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• 2003

This study is performed to investigate the characteristics of the palatal morphology of the children with anterior crossbite in Hellman dental age IIIA by 3-dimensional laser scanner. Totally 40 study casts were taken; 20 were from children with crossbite and another 20 were from normal occlusion as a control. Each cast was scanned by 3 dimension laser scanner and shaped by the 3 dimension image by rapidform 2000 program(INUS, Korea). And finally it was calculated by Rhino 3D program(Rhinoceros, USA). The intercanine, intermolar cross-sectioned transverse plane and sagittal plane were measured. Due to the variations in palatal morphology, each group was standardized into 25mm, 35mm, 35mm. By sectioning standardized curves of the Palatal morphology per 1mm, the palatal depth of each point was calculated. Through these complex methods, the mean curves of the palatal morphology could be obtained and the values were statistically compared and evaluated by T-test with 95% of significance level. The results were as follows: 1. In the intercanine cross-sectioned transverse plane, the mean curve of palatal morphology of crossbite group was flatter V shape than that of control group, however, there was no statistical significance was found between two groups(P>0.05). 2. In the intermolar cross-sectioned transverse plane, the mean curve of palatal morphology of crossbite was deeper all over the area than that of control group, and the statistical significance was found in the middle area from point 8 to 21(P<0.05). 3. In the sagittal plane, the mean curve of palatal morphology of crossbite group was more deepening as approaching posteriorly than that of control group, and the statistical significance was found in all over the area(P<0.01).

• Tuberculosis and Respiratory Diseases
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• v.49 no.1
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• pp.60-71
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• 2000

Backgrounds : Cathepsin D, an aspartic lysosomal proteinase, is believed to be involved in local invasion and metastasis of tumor cells by its proteolytic activity and has been described to be associated with tumor progression and prognosis in some human malignancies including breast cancer. But, its prognostic value for human lung cancer remains to be determined. The purpose of this study is to determine clinicopathological and prognostic significance of cathepsin D expression in non-small cell lung cancer. Method : Using a polyclonal antibody, immunohistochemical analysis of cathepsin D was performed on paraffin embedded sections of tumors obtained surgically from 54 patients with non-small cell lung cancer (37 squamous cell carcinoma, 14 adenocarcinoma, 2 large cell carcinoma, and 1 undifferentiated carcinoma). Results : Eighteen patients (33.3%) showed positive immunoreactivities of cathepsin D in tumor cells. No significant correlation of cathepsin D expression in tumor cells was found in p-stage (surgical-pathologic stage), tumor size, tumor factor, nodal involvement, and differentiation. Of 54 patients, 29 (53.7%) patients showed moderate to massive cathepsin D-positive stromal cells within the tumor tissues, while the rest (46.3%) showed few cathepsin D-positive stromal cells within the tumor tissues. Cathepsin D expression in stromal cells was significantly associated with p-stage in non-small cell lung canær (p=0.031). No significant correlation of the degree of cathepsin D-positive stromal cells was found in tumor size, T -factor, nodal involvement, differentiation Cathepsin D expression status in tumor cells and stromal cells was not significantly associated with prognosis expressed by survival rate. The results of multivariate analyses of variables possibly associated with prognosis showed that nodal involvement was the only independent prognostic factor in all patients. Conclusion : Cathepsin D expression in stromal cells was significantly associated with p-stage in non-small cell lung cancer. However, it was not related to other clinicopathologic features and prognosis, and Cathepsin D expression in tumor was not related to p-stage and prognosis.

• Tuberculosis and Respiratory Diseases
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• v.51 no.4
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• pp.334-345
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• 2001

Background : Pulmonary tuberculosis(TB) is still prevalent and remains a significant clinical problem for the elderly. However, the disease presents in many ways, and there are frequent adverse drug reactions that may prevent the early diagnosis and treatment of elderly TB patients compared to the young. The purpose of this study was to determine whether or not there are any differences in the clinical feature of pulmonary tuberculosis(TB) in both the diagnosis and treatment between the young (less than 64 years) and the elderly (65 years and more). Methods : The medical records of 125 young and 70 elderly pulmonary TB patients, who were diagnosed with and treated for pulmonary TB at the Seoul Municipal Boramae Hospital from November 1991 to January 1997, were analyzed retrospectively. Results : Anorexia(12% vs. 31.4%), general weakness (20.0% vs. 54.3%), dyspnea(21.6% vs. 37.1%) and an abnormal mentality (0.8% vs. 15.7%) were more frequent presenting symptoms in elderly TB patients, whereas hemoptysis (32.8% vs. 10.0%) and fever (BT > $37^{\circ}C$, 58.4% vs. 35.7%) were more frequent in the young. The elderly had a higher number of cardiovascular and chronic obstructive pulmonary diseases as underlying illnesses. In chest PA, there were no differences in the location of the TB lesion, but the appearances were initially diagnosed more frequently as pneumonia or lung cancer (8.8% vs. 30.0%, p<0.05) in the elderly. There was no difference in the detection rate of acid fast bacilli(AFB) in the sputum between the two groups. There were no differences in the treatment response and follow-up loss. However, adverse drug reactions (13.6% vs. 45.7%, p<0.05), and changes in medication (4.9% vs. 25.7%, p<0.05) during treatment occurred more frequently in the elderly. One among the 125 young patients died from tuberculosis whereas 6 among the 70 elderly patients died from the disease. Conclusion : Because the clinical and radiological presentations were more atypical, a sputum AFB smear and culture should be done immediately in the elderly who are TB. The elderly experienced more frequent adverse drug reactions and mortality during treatment, but the response to treatment was good and rapid.

• Tuberculosis and Respiratory Diseases
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• v.51 no.2
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• pp.147-154
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• 2001

Background : Bronchoscopy has been widely used for a histologic diagnosis through a transbronchial lung biopsy or for staging of patients with peripheral lung cancer. However a transthoracic needle aspiration (TTNA) has been used more widely for a histologic diagnosis in patient with a small size nodule or a nodule located in the outer portion of the lung because of the low diagnostic yield of bronchoscopy in these cases. The role of bronchoscopy for staging is not well established in patients with peripheral lung cancer diagnosed by a TTNA or patients who are undergoing surgery without a histologic diagnosis. Method: To evaluate the role of bronchoscopy for the staging in patients with peripheral lung cancer, who were diagnosed by TTNA, the medical records of 86 patients with peripheral lung cancer who underwent bronchoscopyat Kyungpook National University Hospital between January 1995 and May 1997 were reviewed. Results : While 53 cases had normal bronchoscopic findings, 33 cases had abnormal bronchoscopic findings comprising 9 cases of tumor, 10 cases of infiltration and 14 cases of compression of which there were 25 cases of T1 and 8 T2 endoscopically. The bronchoscopic staging did not influence the changes of the clinical stage of lung cancer. The frequencies of bronchial involvement tended to increase as the sizes of the nodule increased. Among the 42 patients who underwent surgery, 9 patients staged higher after operation because of lymph node involvement in 8 patients and the involvement of the pulmonary artery in 1 patient. No case staged above after operation due to a bronchial invasion. Conclusion : These findings suggests that bronchoscopy is not useful for staging in patients with peripheral lung cancer diagnosed by a TTNA.

• Tuberculosis and Respiratory Diseases
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• v.62 no.4
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• pp.276-283
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• 2007

Background: A national health care initiative recommends routine spirometry screening of all smokers over age 45 or patients with respiratory symptoms. In response to the recommendation, new, simple, and inexpensive desktop spirometers for the purpose of promoting widespread spirometric screening were marketed. The performance of these spirometers was evaluated in vivo testing with healthy subjects. However, the clinical setting allows spirometric assessment of various pathologic combinations of flow and volume. Objective: The aim of this study was to compare the accuracy of a desktop spirometer to a standard laboratory spirometer, in a clinical setting with pathologic pulmonary function. Method: In a health check-up center, where screening pulmonary funct test was performed using the HI-801 spirometer. Subjects who revealed the ventilation defect in screening spirometry, performed the spirometry again using the standard Vmax spectra 22d spirometer in a tertiary care hospital pulmonary function laboratory. Pulmonary function test with both spirometer was performed according to the guidelines of the American Thoracic Society. Results: 109 patients were enrolled. Pulmonary function measurements (FVC, $FEV_1$, PEFR, FEF25%-75%) from the HI-801 correlated closely (r=0.94, 0.93, 0.81, 0.84, respectively) with those performed with the Vmax spectra 22d and showed the good limits of agreement and differences between the 2 devices; FVC +0.35 L, $FEV_1$ +0.16 L, PEFR +1.85 L/s, FEF25%-75%-0.13 L/s. With the exception of $FEV_1$, FEF25%-75%, these differences were significant(p<0.05) but small. Conclusion: The HI-801 spirometer is comparable to the standard laboratory spirometer, Vmax spectra 22d, with high accurary for $FEV_1$ and FVC and acceptable differences for clinical use.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.12 no.3
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• pp.65-74
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• 2017

There have been questions how entrepreneurs think, act and why individuals become entrepreneurs. The trait-based explanation of entrepreneurial activities has been main stream. However, the trait-based theory has been criticized because it assumes that entrepreneurial traits are inherited, stable and enduring over time. This research accepts the cognitive theory to see how entrepreneurs learn or accept others' values, how entrepreneurial perceptions of opportunity impact entrepreneurial actions and how individuals acquire the social legitimation of the formation of entrepreneurial activities. In order to capture the attitudes, activities and motivations of people who are involved in entrepreneurial activities, the author uses the GEM Korea 2016 data. The data from the Global Entrepreneurship Monitor(GEM) has been well known for the data to capture individuals early-stage entrepreneurial activities. This paper used the sample from the APS(Adult Population Survey) of the GEM which was completed by a representative sample of two thousand adults in Korea by the qualified survey vendor, with strict procedures and oversight by the GEM central data team. The hypotheses are tested with logit regression analysis to estimate the probability of the influence of perceptual variables such as individual perception in social learning, the opportunity recognition in the environment, and social legitimation in the entrepreneurial activities. Based on the results, individuals tend to have high entrepreneurial activities if individuals have high self-efficacy. Also, the existence of role models around the entrepreneurs encourages the individuals involve in entrepreneurial activities more however the perception of opportunity in the environment is not strongly associated with entrepreneurial activities. The media exposure of successful entrepreneurs is more important than others' perception of entrepreneurs on the desirable career option or respect from communities. This paper can contribute to the cognitive processes, particular perception about oneself, as well as perception which is impacted by a community or a society.

• Progress in Medical Physics
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• v.25 no.1
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• pp.37-45
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• 2014

The accuracy and uniformity of CT numbers are the main causes of radiation dose calculation error. Especially, for the dose calculation based on kV-Cone Beam Computed Tomography (CBCT) image, the scatter affecting the CT number is known to be quite different by the object sizes, densities, exposure conditions, and so on. In this study, the scatter impact on the CBCT based dose calculation was evaluated to provide the optimal condition minimizing the error. The CBCT images was acquired under three scatter conditions ("Under-scatter", "Over-scatter", and "Full-scatter") by adjusting amount of scatter materials around a electron density phantom (CIRS062, Tissue Simulation Technology, Norfolk, VA, USA). The CT number uniformities of CBCT images for water-equivalent materials of the phantom were assessed, and the location dependency, either "inner" or "outer" parts of the phantom, was also evaluated. The electron density correction curves were derived from CBCT images of the electron density phantom in each scatter condition. The electron density correction curves were applied to calculate the CBCT based doses, which were compared with the dose based on Fan Beam Computed Tomography (FBCT). Also, 5 prostate IMRT cases were enrolled to assess the accuracy of dose based on CBCT images using gamma index analysis and relative dose differences. As the CT number histogram of phantom CBCT images for water equivalent materials was fitted with a gaussian function, the FHWM (146 HU) for "Full-scatter" condition was the smallest among the FHWM for the three conditions (685 HU for "under scatter" and 264 HU for "over scatter"). Also, the variance of CT numbers was the smallest for the same ingredients located in the center and periphery of the phantom in the "Full-scatter" condition. The dose distributions calculated with FBCT and CBCT images compared in a gamma index evaluation of 1%/3 mm criteria and in the dose difference. With the electron density correction acquired in the same scatter condition, the CBCT based dose calculations tended to be the most accurate. In 5 prostate cases in which the mean equivalent diameter was 27.2 cm, the averaged gamma pass rate was 98% and the dose difference confirmed to be less than 2% (average 0.2%, ranged from -1.3% to 1.6%) with the electron density correction of the "Full-scatter" condition. The accuracy of CBCT based dose calculation could be confirmed that closely related to the CT number uniformity and to the similarity of the scatter conditions for the electron density correction curve and CBCT image. In pelvic cases, the most accurate dose calculation was achievable in the application of the electron density curves of the "Full-scatter" condition.

• Clinical and Experimental Pediatrics
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• v.52 no.1
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• pp.87-92
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• 2009

Purpose : Many gene polymorphisms are associated with coronary artery abnormalities in Kawasaki disease. Catechol-O- methyltransferase (COMT) plays an important role in the metabolism of catecholamines, catechol estrogen, and catechol drugs. Polymorphisms of the COMT gene are reported to be associated with myocardial infarction and coronary artery abnormalities. The aim of this study was to evaluate the relationship between COMT gene polymorphisms and coronary artery abnormalities in Kawasaki disease patients. Methods : One hundred and one Korean children with Kawasaki disease and 306 healthy Korean control subjects were enrolled in this study. The polymorphisms of the COMT gene were analyzed by direct sequencing. Results : There were no differences in the genotype and allelic frequency of the rs4680 and rs769224 polymorphic sites between Kawasaki disease and control subjects. Further, no significant difference was found in the rs4680 polymorphism between patients with coronary artery abnormalities and patients without coronary artery abnormalities (codominant P=0.32, dominant P=0.74, recessive P=0.13). However, the distribution of the rs769224 polymorphism was significantly different between patients with coronary artery abnormalities and patients without coronary artery abnormalities (codominant P= 0.0077, dominant P=0.0021, recessive P=0.16). Conclusion : Our results indicate that the polymorphisms of the rs769224 gene might be related to the development of coronary artery abnormalities in Kawasaki disease.

• Journal of Bio-Environment Control
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• v.16 no.4
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• pp.322-327
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• 2007

This study was conducted to analysis the chemical properties of Peunggang river and investigate the effect of irrigation sources on the growth of tomato and cucumber. The salt concentration in Peunggang river was high by $3.22{\sim}3.62dS{\cdot}m^{-1}s$ from March to May and lower gradually from April to February of next year, which was also lower in upper stream than in middle or low stream of Peunggang river. The growth such as plant height, fresh weight and dry weight in tomato and cucumber was better in drain water and tap water irrigation than in PR water (Peunggang river) irrigation. Mean fruit weight was highest in the tap water, and that of cucumber was no significance in the treatments. The number of setting fruit was lower in the PR water than in the treatments, and which was no significance between rain water and tap water. The yield of tomato and cucumber was found to be highest by 10,594 and 11,826 kg/10a in tap water, respectively and also lowest in the PR water among the three treatments. The fruit quality, soluble solids of tomato shows a tendency to increase in the PR water as compared with the other treatment, and the rate of blossom-end rote was higher by 13.6% in the PR water. T-N and P content of tomato and cucumber were no significance in the treatments. Ca content was lowest, but Na content highest in the PR water. It was thought that a rain water and tap water as alternative irrigation source of a PR water were proper.