• Journal of Microbiology and Biotechnology
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• v.28 no.6
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• pp.917-930
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• 2018

Intracellular synthesis of silver/silver chloride nanoparticles (Ag/AgCl-NPs) using Meyerozyma guilliermondii KX008616 is reported under aerobic and anaerobic conditions for the first time. The biogenic synthesis of Ag-NP types has been proposed as an easy and cost-effective alternative for various biomedical applications. The interaction of nanoparticles with ethanol production was mentioned. The purified biogenic Ag/AgCl-nanoparticles were characterized by different spectroscopic and microscopic approaches. The purified nanoparticles exhibited a surface plasmon resonance band at 419 and 415 nm, confirming the formation of Ag/AgCl-NPs under aerobic and anaerobic conditions, respectively. The planes of the cubic crystalline phase of the Ag/AgCl-NPs were confirmed by X-ray diffraction. Fourier-transform infrared spectra showed the interactions between the yeast cell constituents and silver ions to form the biogenic Ag/AgCl-NPs. The intracellular Ag/AgCl-NPs synthesized under aerobic condition were homogenous and spherical in shape, with an approximate particle size of 2.5-30nm as denoted by the transmission electron microscopy (TEM). The reaction mixture was optimized by varying reaction parameters, including temperature and pH. Analysis of ultrathin sections of yeast cells by TEM indicated that the biogenic nanoparticles were formed as clusters, known as nanoaggregates, in the cytoplasm or in the inner and outer regions of the cell wall. The study recommends using the biomass of yeast that is used in industrial or fermentation purposes to produce Ag/AgCl-NPs as associated by-products to maximize benefit and to reduce the production cost.

• Bulletin of the Society of Naval Architects of Korea
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• v.27 no.4
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• pp.27-31
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• 1990

To calculate the lift of a thin lifting surface like the ship-rudder, it is popular to replace the lifting surface by a series of vortices. Two methods, which are vortex lattice method and mode function method, are frequently used to distribute the vortices on the lifting surface. In this paper, the intermediate way of two mentioned calculation method is carried out to exploit the merits of them. The basic concept of this method is to divide the lifting surface with several strips in span-wise and replace vortices to the chord-wise at each strips. A horn type semi-balanced rudder is chosen for the real method, and the validity of the proposed calculation is pursued by the open water test of the same rudder. Finall, this method is applied to the calculation of the interference between the two homogenous rudders siting parallel to the free stream.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.201-206
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• 2006

A recent laboratory study has demonstrated improved caries lesion resistance with enamel that was exposed to $CO_2$ laser irradiation for very short time period. When topical fluoride treatment was performed before or after laser irradiation, reductions in dental caries. The purpose of this scanning electron microscopic(SEM) study and atomic force microscope study was to characterize surface alterations in tooth enamel after in vitro laser irradiation alone and combined topical fluoride treatment either before or after laser irradiation. The treatment effects of laser irradiation led to the formation of an irregular, mild porosities and fine fissures, also created granular materials. But when laser irradiation was followed by APF, the enamel surface had homogenous architecture. The result led to the caries resistance effects by these granular structures have been considered to represent redeposited mineral phases due to the mobilization of calcium, phosphate, and fluoride from lased enamel.

• Tuberculosis and Respiratory Diseases
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• v.46 no.3
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• pp.432-437
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• 1999

Benign fibrous mesothelioma of the pleura is a relatively rare neoplasm originated from pleural mesothelial cell, often asymptomatic or presenting with a specifical sign. One of the main problems, concerns the preoperative differential diagnosis, mainly because it is difficult to differentiate between benign and malignant type. A 62-year old woman presented with recurrent chest pain. The chest radiography in a patient was suspected localized pleural mesothelioma. The chest computed tomography scan showed that mass like lesion of well marginated ovoid shape with homogenous attenuation on anterior-basal segment of right lower lobe. After resection of a pleural mass by thoracoscopic extirpation from right hemithorax, Localized benign fibrous mesothelioma of the pleura was confirmed by pathology and immunohisto-chemical staining. We report here one case of pleural benign fibrous mesothelioma with some considerations on its diagnosis and treatment.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.10a
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• pp.1630-1637
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• 2008

Jeju-do is a island formed by the volcanic activity and has more than 360 volcanic cones distributed widely along the long axis of the elliptically shaped island. The volcanic cones consist mainly of scoria, so called "Song-I" in the local dialect. In this study the chemical and soil mechanical properties of scoria being very different from those of the inland were investigated with the various tests. In the sieve-passing test the particle size of scoria had more than 10 of uniformity coefficient and gradation coefficient of 1 ~ 3, showing relatively homogenous distribution. Based on the uniformity classification, scoria was assorted into GW. In the large scale direct shear tested for measuring the mechanical strength of scoria the internal friction angle of red scoria was $37^{\circ}$ and that of black scoria was $36^{\circ}$. This indicated that there was no difference in the mechanical strength between two types of scoria. On the other hand, red and black scoria had $1.24{\times}10^{-3}$ to $3.55{\times}10^{-2}$ cm/sec of k values for the static water level permeability, thus being classified into a coarse or fine sand as compared with that representing the saturated soil. They also had 1.411 to $1.477\;g/cm^3$ of notably low $r_{dmax}$ values for the compaction test as compared with common soil, which was considered to be due to their low specific gravity and high porosity. In conclusion, the soil mechanic properties of scoria obtained from this study are thought to be very helpful for reducing lots of trial and error happening in the civil engineering construction.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.610-613
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• 2009

New rod-disc liquid crystal (LC) molecule RD12 (12 is the number of carbon atoms between the rod and disc mesogenic liquid crystals) was synthesized via the chemical attachment of six cyanobiphenly calamitic mesogens linked to the triphenyl discotic mesogen with six alkyl chain linkage. Aligning characteristics associated with homogenous alignment is investigated at first and then field-dependent molecular reorientation under a vertical electric field is studied. Interestingly, they show abnormal slow molecular transition from initiate state (no electric field condition) to certain voltage. In this condition, we observe the molecular competition during reorientation. However, once a tilting direction of disk molecules are defined, the frustration is not observed anymore. The origin of this phenomenon is explained with a suggested model for the first time.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.18 no.1
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• pp.115-119
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• 1996

Myoepithelioma is composed exclusively of myoepithelial cells. Myoepithelial cells are ectodermally derived contractile cells that can be routinely identified in many normal tissues having secretory function such as major and minor salivary glands, lacrimal gland and sweat gland. Tumors composed exclusively of myoepithelial cells, so-called myoepitheliomas, are rare-less than 1% of all salivary gland tumors. Grossly, these tumors are well demarcated. The external surface is smooth and may be bosselated. The cut surface is white and homogenous. Microscopically, these tumors are surrounded by a thin fibrous capsule. They are composed of benign-appearing spindle- shaped and/or polygonal cells. Mitoses are rare. Frequently these tumors contain myxomatous stroma which is susceptible to alcial blue stain. Clinically, myoepitheliomas present as slow-glowing, painless masses and can not distinguished from pleomorphic adenomas. Treatment is the same as for pleomorphic adenoma, and the surgical excision should include a margin of normal tissue. Although the majority of myoepitheliomas have behaved in a beingn manner, pleomorphism and mitotic activity have been associated with local aggressiveness.

• Tuberculosis and Respiratory Diseases
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• v.52 no.2
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• pp.174-178
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• 2002

Primary pulmonary amyloidosis is a rare condition that can be classified into the tracheobronchial, diffuse alveolar septal, and nodular parenchymal type. Tracheobronchial amyloidosis is characterized by deposition of fibrilar proteins in the tracheobronchial tree, and it can be subdivided into diffuse and focal varieties. In this report, a case of diffuse tracheobronchial amyloidosis confirmed by flexible fiberoptic bronchoscopic biopsy is presented. The patient was a 43-year old male with a chief complaint of cough and sputum for 20 days and dyspnea for one day. The chest CT scan showed diffusely thickened walls of both the main and lobar bronchi with calcification. The bronchoscopic findings showed nodular lesions of the trachea, a diffuse bronchial stenosis of both the main bronchi and a pinpoint narrowing of the left upper and right middle lobar bronchus. The biopsy showed submucosal deposits of homogenous eosinophilic amyloid materials and an apple-green birefringence under polarizing microscopy following the Congo-red stain.

• Tuberculosis and Respiratory Diseases
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• v.45 no.2
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• pp.437-443
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• 1998

Pulmonary alveolar proteinosis is characterized by the accumulation of PAS positive lipoproteinaceous or amorphous proteinaceous material in the alveolar space with spared delicate septal architecture of the lung interstitium and impaired gas exchange of alveoli. We experienced a case of secondary pulmonary alveolar proteinosis in a 41 year old male patient who have occupational history of engagement as a mason over 4year. He compalined exertional dyspnea and chest discomfort, and presented fine inspiratory crackle at both lower lung field, numerous fine nodular denisties in both lung field with peripheral sparing. Light microscopic finding of lung tissue obtained by transbronchiallung biopsy revealed homogenous eosinophilic colloid-like luminal content in the alveolar space, and electron microscopy of bronchoalveolar lavage fluid concentrate showed electron-dense multilamellated structures. To treat the disease, we tried whole lung lavage of right lung with isotonic saline under general anesthesia. After whole lung lavage of right lung, he showed markid improvement of symptom and partial improvement of chest X-ray findings. The patient has been followed for 12 month until now, with no evidence of aggravation.

• Advances in pediatric surgery
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• v.2 no.1
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• pp.64-67
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• 1996

Aberrant migration of thymic tissue occurs as an ectopic thymus in the mediastinum, base of skull, tracheal bifurcation, and cervical region. A recent review of the literature by Nowak et al. showed over 70 reported cases of aberrant thymus or thymic cyst in patients who presented with primary neck masses. Authors experienced a case of ectopic cervical thymus and reviewed the literature. A one-year-old boy with left neck swelling which had been noticed since one month of age visited out patient clinic. Ultrasonography showed a well-defined cystic mass containing homogeneous, low-echogenic content locating in the lateral aspect of the left carotid sheath. Operation was performed under the impression of branchial cleft cyst. At surgery, a multiseptated, well-encapsulated, brownish and doughy mass which was extending into the vicinity of the carotid bifurcation with sland stalk-like portion ending between the hypoglossal nerve and external carotid artery was excised completely. The cut-surface showed homogenous solid mass, and on frozen section the tissue revealed a normal thymic histology. Postoperative ultrasonography showed bilateral thymus in the superior mediastinum. The patient has no immunologic problem and is doing well now.