• Laser Solutions
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• v.2 no.2
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• pp.42-51
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• 1999

This study has been performed to investigate into some effects of the output power and traverse speed of laser beam on the microstructures, hardness and fatigue resistance of the ductile iron surface-hardened by $CO_2$ laser defocussed beam. Optical micrographs have shown that with increasing the output power and decreasing the traverse speed, the martensite was coarsened and some retained austenite were appeared in ductile iron. The microstructures of hardening zone were composed of bull's eye and some nodular graphite dissolved structures by the effect of self quenching. Fatigue fracture characteristics of ductile iron have appeared in the high stress and low stress ranges. The fracture initiated at nodular graphites in the surface hardened layer due to the stress concentration caused by a notch effect. The interior graphite nodules were broken away or popped out during crack propagation. Fatigue test has shown that values of fatigue strength considerably increased with increasing output power at a given traverse speed.

• Korean Journal of Veterinary Service
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• v.16 no.1
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• pp.57-64
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• 1993

This survey was performed to report rare outbreak of liver cirrhosis in Korean native goat (KNG) which was died of Yangpyeong's goat farm on Feb. 1992. The examination for the KNG was carried out by clinical signs, necropsy and various lab-oratory test including parasitic, bacterial and histological test. The KNG looked jaundice, ascite, hemorrhage of lumen, abomasum and intestine, and brownish smooth cirrhotic liver at necropsy. Histological examination for liver revealed considerable proliferation of connective tissue and piecemeal necrosis which was caused by chronic active inflammation in interlobules and intralobules. There were atrophic micro and macro nodules which were sur-rounded by connective tissue. The lobular structure lack almost all central vein. The portal areas appearred proliferation of bile ducts, blood vessels and connective tissues. These connective tissue infiltrated heavily with plasma cells, Iymphocytes and histocytes. Histological examination for brain proved to be hepatic encephalopathy by virture of congestion and edema in cerebral medullary. From these results were demonstrated miked nodular, active, postnecrotic liver cirrhosis.

• Proceedings of the KSMRM Conference
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• 2006.11a
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• pp.85-85
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• 2006

• Tuberculosis and Respiratory Diseases
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• v.59 no.2
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• pp.204-208
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• 2005

Herein, we report a case of tumorous endobronchial tuberculosis with successful recovery of atelectasis without any significant bronchial stricture, after repeated expectorations of nodular tissues. A 24-year-old male patient was presented with persistent cough. The patient was diagnosed to be suffering from tuberculous lymphadenitis on right axillar and mediastinum of lung, and was subsequently treated with antituberculosis agents. After two months, clinical deteriorations and atelectasis were observed on right upper lobe of lung. Multiple endobronchial tumorous lesions, which obstructed the right main bronchus, were revealed on bronchoscopy, and based on the endobronchial biopsy findings we confirmed that the patient was suffering from endobronchial tuberculosis. We decided to administer antituberculosis agents without any additional procedure. After few weeks, the patient spontaneously expectorated nodular tissues with vigorous coughing. Later on, the symptoms and atelectasis disappeared and the patient was completely recovered. This case shows that in patients suffering from tumorous endobronchial tuberculosis, endobronchial mass can be expectorated spontaneously without sequelae of significant bronchial stenosis.

• Tuberculosis and Respiratory Diseases
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• v.69 no.3
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• pp.212-216
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• 2010

Nodular lymphoid hyperplasia is a very rare benign disease and usually shows consolidation on chest X-ray with symptoms of pneumonia due to the proliferation of lymphoid cells in the lung parenchyma. It is common for patients to be diagnosed with pneumonia and treated with antibiotics, but patients often enter a cycle of repeated improvement, followed by aggravation of symptoms. At this point, surgical diagnostic tools are considered in order to differentiate between malignant disease and interstitial lung disease. Here, we report 2 cases of patients with nodular lymphoid hyperplasia and review the associated references.

• Tribology and Lubricants
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• v.35 no.6
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• pp.356-361
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• 2019

The friction and wear between machine components directly influence the energy loss and failure in various machines. Therefore, there is always a demand for finding methods to reduce friction and wear. Of the possible methods, lubrication is a widely used method for reducing friction and wear. In the case of lubrication, it is important to analyze the tribological behavior in the boundary lubrication because most of friction and wear occurs in the boundary lubrication regime. Cast iron has been regarded as a good material for industrial applications due to the excellent mechanical properties and high productivity. Especially, nodular cast iron is a material that shows better mechanical properties and wear-resistance compared with cast iron due to inclusion of spheroidal graphite. In this work, we investigated the tribological characteristics of nodular cast iron with respect to different counter parts in boundary lubrication regime. Sliding tests were conducted with SUJ2, ZrO₂, Si₃N₄ balls as counter parts using a pin-on-disk type tribotester. The results showed different friction and wear behaviors with different counter parts. The case of ZrO₂ showed the lowest wear rate in specimen and no significant ball wear. In case of SUJ2, it showed similar wear rate with ZrO₂ case in specimen and the highest friction coefficient. The case of Si₃N₄ showed the lowest friction coefficient, 33% lower than the case of SUJ2. It showed 16.9 times larger wear rate in specimen and 43% larger wear rate in ball compared to that of the SUJ2 case.

• Economic and Environmental Geology
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• v.30 no.3
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• pp.263-275
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• 1997

Compound calcrete deposits are recognized from the Dadaepo Formation in Dusong peninsula, Pusan, and their textures, structures, morphology, and stratigraphic distribution are examined. The Dadaepo Formation in study area consists of fluvial plain deposits including floodplain-lake deposits, and the compound calcrete deposits occur above floodplain deposits and below lacustrine deposits. The compound calcrete deposits are composed of nodular to massive (micritic), laminar, nodular, nodular to massive (marly), and marly calcrete deposits. In these calcretes, circumgranular and curved cracks, alveolar structures, fitted peloids, tubular fenestrae with laminar micrite wall (rootlet casts), microstalactic calcite, and tepee structures are observed, which indicates that they are calcic paleosols. Considering their stratigraphic occurrences and pedogenic origin, compound calcrete deposits are interpreted to have formed on distal fluvial plain to palustrine environment by the repetetion of deposition and subsequent calcification due to alternation of lake expansion and contraction. The repetetion of calcrete formation suggests that arid climatic condition was alternated with humid condition in short-term period. Such alternated paleoclimatic condition is similar to those of the Sindong and Hayang groups, and indicates that short-term fluctuations from arid to humid climate were prevailing in overall Gyeongsang Basin. In stratigraphic sense, the compound calcrete deposits can be used as a marker deposit for the correlation of the Dadaepo Formation.

• Imaging Science in Dentistry
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• v.48 no.3
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• pp.185-190
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• 2018

Purpose: The aim of this study was to compare the location and the shape of the mandibular lingula in skeletal class I and III patients using panoramic radiography and cone-beam computed tomography. Materials and Methods: The sample group included 190 skeletal class I patients and 157 class III patients. The location of the lingula in relation to the deepest point of the coronoid notch was classified into 3 types using panoramic radiographs. The shapes of the lingulae were classified into nodular, triangular, truncated, or assimilated types using cone-beam computed tomographic images. The data were analyzed using the chi-square test. Results: The tips of the lingulae were at the same level as the coronoid notch in 75.3% of skeletal class I patients and above the coronoid notch in 66.6% of class III patients. The positions of the lingulae in relation to the deepest point of the coronoid notch showed statistically significant differences between class I and class III patients. The most common shape was nodular, and the least common was the assimilated shape. Although this trend was not statistically significant, the triangular shape was more frequently observed in class III patients than in class I patients. Conclusion: The locations and the shapes of the mandibular lingulae were variable. Most of the lingulae were at the same level as the coronoid notch in skeletal class I patients and above the coronoid notch in skeletal class III patients. The nodular and assimilated-shaped lingulae were the most and the least prevalent, respectively.

• Tuberculosis and Respiratory Diseases
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• v.43 no.3
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• pp.467-471
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• 1996

We report a case of a 20-year-old woman who presented with fever, dry cough and pulmonary consolidation at the left upper lobe on chest radiograph. Fiberoptic bronchoscopy revealed obstruction of the left upper lobar bronchus with exophytic mass and multiple nodular protruding lesions at the left main bronchus. Endobronchial actinomycosis was confirmed by demonstration of sulfur granule through the bronchoscopic biopsy of nodular lesion. Intravenous administration of penicillin G followed by oral tetracycline therapy for 5 months resulted in complete recovery of symptoms which had been present for 3 months prior to therapy. Infiltrative consolidation on the chest X-ray disappeared and all the lesions shown by bronchoscopy were nearly normalized after 6 months only to remain small nodular remnants at the left main bronchus. Endobronchial actinomycosis should be included in the differential diagnosis of endobronchial mass.

• International journal of thyroidology
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• v.11 no.2
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• pp.123-129
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• 2018

Background and Objectives: Hypermethylation of the tumor suppressor gene RASSF1A and activating mutation of BRAF gene have been recently reported in thyroid cancers. To investigate the role of these two epigenetic and genetic alterations in thyroid tumor progression, methylation of RASSF1A and BRAF mutation were examined in thyroid tumors. Materials and Methods: During 2007 to 2017, 69 papillary carcinomas, 18 nodular hyperplasia, 3 follicular carcinomas, and 13 follicular adenomas were selected. The methylation-specific polymerase chain reaction (MSP) technique was used in detecting RASSF1A methylation and polymerase chain reaction (PCR)-single-stranded conformation polymorphism and sequencing were used for BRAF gene mutation study. Results: The hypermethylation of the RASSF1A gene was found in 84.6%, 100% and 57.9% of follicular adenomas, follicular carcinomas, and papillary carcinomas, respectively. Nodular hyperplasia showed a hypermethylation in 33.3%. The BRAF mutation at V600E was found in 60.7% of papillary carcinoma and 27.0% of nodular hyperplasia, but none of follicular neoplasms. The BRAF mutation was correlated with the lymph node metastasis and MACIS clinical stage. There is an inverse correlation between RASSF1A methylation and BRAF mutation in thyroid lesions. Conclusion: Epigenetic inactivation of RASSF1A through aberrant methylation is considered to be an early step in thyroid tumorigenesis, and the BRAF mutation plays an important role in the carcinogenesis of papillary carcinoma, providing a genetic marker.