• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.2
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• pp.81-93
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• 2006

Obstructive sialadenitis is one of common disease in salivary gland, and most common histologic features are loss of acinar cell and ductal dilatation associated with fibrosis, and infiltration of inflammatory cells. Although many experimental studies has been accomplished for the salivary acinar cell change in obstructive salivary gland disease, studies for myoepithelial cell were deficient. This study is designed for salivary gland tissue change, especially myoepithelial cell when nonspecific chronic sialadenitis or salivary duct injury by duct obstruction or cut can be occurred that is common encounted clinically. After ligation and cutting of submandibular gland of rabbit, groups of aminmal were sacrificed at 1, 2, 4 weeks postoperatively, submandibular gland were removed. The histopathologic evaluation was done with light microscopy. And, with immunohistochemical staining with ${\alpha}$-smooth muscle actin, characteristics of myoepithelial cell were examined. With transmission electron microscopy, ultrastructure of myoepithelial cell were examined for distribution and ultrastructure of myoepithelial cell. The results were obtained as follows: 1. In the histopathologic evaluation, ligation and cutting group of 1 week, linkage of myoepithelial cell associated with acinar atrophy and degeneration were disappeared in both group. 2. More prominent squamous metaplasia was seen in acinar cells of ligation group of 2 weeks experimental rabbit than cutting group. 3. Acinar cells are nearly disappeared in both ligation and cutting group of 4 weeks, and myoepithelial cell also disappeared associated with acinar cell atrophy, and duct-like structure composed by squamous cells by squamous metaplasia in acinar cells were distributed. 4. In immunohistochemical study, both ligation and cutting group ${\alpha}$-SMA distribution were diminished at 1 week experimental rabbits, but myoepithelial cell was more diminished in ligation group than cutting group, which were distributed around cells of squamous metaplasia. 5. Nuclear condensation, chromosome margination, and cytoplasmic vaculoation were appeared in myoepithelial cell of both cutting and ligation group after 1 week with transmission electron microscopy. But degenerative substance were seen in cytoplasm of myoepithelial cell of ligation group of 4 weeks. From the results obtained in this study, atrophy and degeneration of myoepithelial cell was more prominent in duct ligation group than duct cutting group, and myoepithelial cells were seen around cells squamous metaplasia of acinar cell.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.23 no.1
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• pp.32-37
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• 2014

Open-cell silicon foam is difficult to cut using conventional machining processes because of its low stiffness. That is, open-cell silicon foam is easily pressed down when the tool is engaged, which makes it difficult to remove the material in the form of chip. This study proposes an advanced method of machining open-cell silicon foam by freezing the material using liquid nitrogen. Furthermore, the machining conditions are optimized to maximize the efficiency of material removal and minimize the usage of liquid nitrogen by conducting experiments under various machining conditions. The results show that open-cell silicone foam products with free surface can be successfully machined by employing the proposed method.

• Applied Microscopy
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• v.13 no.1
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• pp.41-47
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• 1983

A Scanning electron microscope which can obtain additional information not readily available with either the light or transmission electron microscope was used to study the mast cell shape and its granules in normal mammal tissue(rat mesentery, stomach and mouse stomach) by fretting cut using liquid nitrogen. The results showed that rat mesentery and mouse stomach mast cell surfaces had no ridges and microvilli, but revealed several microvilli projecting into the surrounding connective tissue in the rat stomach mast cell. The shape of the mast cell varied from discoid(in the rat mesenteric mast cell) to ellipsoid (rat and mouse stomach), ranging from 7.5 to $10{\mu}m$ in diameter. The shape of the nucleus was ellipsoid and nucleic membrane was adherent to the outer surface of the granules. The granules, approximately 0.2 to $0.9{\mu}m$ in diameter, were various shapes. Frequently, rounded protrusions of cytoplasmic granules could be discerned under the cell membrane. Many small granules were seen in the cytoplasm.

• Journal of KIISE:Software and Applications
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• v.33 no.8
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• pp.681-691
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• 2006

Clustering is one of widely used methods for grouping thousands of genes by their similarities of expression levels, so that it helps to analyze gene expression profiles. This method has been used for identifying the functions of genes. Fuzzy clustering method, which is one category of clustering, assigns one sample to multiple groups according to their degrees of membership. This method is more appropriate for analyzing gene expression profiles because single gene might involve multiple genetic functions. Clustering methods, however, have the problems that they are sensitive to initialization and can be trapped into local optima. To solve these problems, this paper proposes an evolutionary fuzzy clustering method, where adaptive a-cut based evaluation is used for the fitness evaluation to apply different criteria considering the characteristics of datasets to overcome the limitation of Bayesian validation method that applies the same criterion to all datasets. We have conducted experiments with SRBCT and yeast cell-cycle datasets and analyzed the results to confirm the usefulness of the proposed method.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.40 no.12
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• pp.761-768
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• 2016

Membranes are used to separate pure gas from gas mixtures. In this study, three different types of mass transport through a membrane were developed in order to investigate the gas separation capabilities of a membrane. The three different models typically used are a lumped model, a multi-cell model, and a discretization model. Despite the multi-cell model producing similar results to a discretization model, the discretization model was selected for this investigation, due to the cell number dependence of a multi-cell model. The mass transport model was then used to investigate the effects of pressure difference, flow rate, total exposed area, and permeability. The results showed that the pressure difference increased with the stage cut, but the selectivity was a trade-off for the increasing pressure difference. Additionally, even though permeability is an important parameter, the selectivity and stage cut of the membrane converged as permeability increased.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.24 no.10B
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• pp.1885-1894
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• 1999

The higher mode cutoff frequencies in Crawford TEM cells computed by the Galerkin method(GM) describe in this paper. The authors also report the half mode boundaries to solve not only the cut-off frequencies of symmetric TEM cells and those of asymmetric TEM cells. It is shown that the measured resonant frequencies of the present symmetric TEM cells and a designed asymmetric TEM cell are agreed with the calculated results.

• Food Science and Preservation
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• v.11 no.2
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• pp.160-169
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• 2004

This study was carried out to investigate the efficacy of electrolyzed water manufactured with or without diaphragm on sterilization and preservation of cut-celery and shelled raw oyster. In cut-celery, total viable cell count and coliform group in the treatment of electrolyzed water were decreased to about 1/200∼1/1,000 level and about 1/100 level comparing non-treated ones. But moisture content, pH, hardness, vitamin C and residual chlorine content were showed a little difference among treatments up to 10 days at 10$^{\circ}C$. L and a color values were gradually increased in all treatments, and color differences($\Delta$E) were remarkable between treatment and untreatment sample. In overall acceptability, cut-celery treated with electrolyzed water showed somewhat higher score than that of other ones treated with tap water and 100 ppm NaClO solution until 5 days of storage. After 48 hours of storage, it was showed that VBN, total viable cell count and coliform count of shelled raw oyster treated with electrolyzed alkali water produced by non-diaphragm system are lower by about 3 mg%, 1∼2 log cycle and 2 log cycle respectively than that of ones treated with sea water. Total viable cell count of shelled raw oyster just after treatment was lower by about 1 log cycle than that of ones treated with sea water, and any significant increment was not found after 24∼48 hours of storage.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.11
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• pp.4719-4722
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• 2015

Background: This study aimed to determine the utility and a cut-off level of serum squamous cell carcinoma antigen (SCC-Ag) to predict lymph node metastasis in locally advanced cervical cancer cases. We also investigated the correlation between SCC-Ag level and lymph node status. Materials and Methods: From June 2009 to June 2014, 232 patients with cervical cancer stage IB2-IVA, who were treated at Ramathibodi Hospital, were recruited. Receiver operating characteristic (ROC) curves were used to identify the best cut-off point of SCC-Ag level to predict lymph node metastasis. Quantile regression was performed to evaluate the correlation between SCC-Ag levels and pelvic lymph node metastasis, paraaortic lymph node metastasis, and parametrial involvement as well as tumor size. Results: Pelvic lymph node metastasis and paraaortic lymph node metastasis were diagnosed in 46.6% and 20.1% of the patients, respectively. The median SCC-Ag level was 6 ng/mL (range, 0.5 to 464.6 ng/mL). The areas under ROC curves between SCC-Ag level and pelvic lymph node metastasis, paraaotic lymph node metastasis, parametrial involvements were low. SCC-Ag level was significantly correlated with paraaortic lymph node status (p=0.045) but not with pelvic lymph node status and parametrial involvement. SCC-Ag level was also related to the tumor diameter (p<0.05). Conclusions: SCC-Ag level is not a good predictor for pelvic and paraaortic lymph node metastasis. However, it is still beneficial to assess the tumor burden of squamous cell carcinoma of the cervix.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.15
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• pp.6591-6594
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• 2015

Background: Mantle-cell lymphoma (MCL) is a unique entity of peripheral B-cell lymphoma that has a discrete morphologic, immunologic, and genetic phenotype, with more common 'classic' and less frequent 'blastoid' and 'pleomorphic' variants, associated with an aggressive clinical course. The aim of this study was to analyze proliferation (Ki-67) indices of 'classic' (c-MCL) and 'blastoid' (b-MCL) variants of a cohort of MCL and to suggest cut off values for the Ki-67 proliferation index in these two subsets. Materials and Methods: MCL cases diagnosed over $4{\frac{1}{2}}$ years at Section of Histopathology, Department of Pathology and Laboratory Medicine, Aga Khan University Hospital, Karachi were retrieved and reviewed. Ki-67 labelling was scored and analysed. Results: A total of 90 of cases of MCL were scrutinized. Mean age ${\pm}SD$ was $60.2{\pm}12.5$ years and the male to female ratio was 4:1, with 67 (75%) cases of c-MCL and 23 (25%) cases of b-MCL. Most samples were lymph node biopsies (n=68), whereas the remainder were from various extranodal sites The mean Ki-67 proliferation index was $29.5%{\pm}14.4%$ in classic variants and $64.4{\pm}15.2%$ for the blastoid variant, the difference being statistically significant (p = 0.029). Conclusions: It was concluded that differential cut-off values of Ki-67 labeling may be used in more objective way to reliably classify MCL into classic or blastoid variants by diagnostic pathologists. We propose a < 40 proliferative index to be suggestive of c-MCL and one of > 50 for the blastoid variant.

• Proceedings of the KSME Conference
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• 2001.11b
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• pp.523-528
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• 2001

There are many difficult problems in analyzing the flow characteristics in a high voltage circuit breaker such as shock wave and complex geometries, which may be either static or in relative motion. Although a variety of mesh generation techniques are now available, the generation of meshes around complicated, multicomponent geometries like a gas circuit breaker is still a tedious and difficult task for the computational fluid dynamics. This paper presents the computational method for analyzing the compressible flow fields in a high voltage gas circuit breaker using the Cartesian cut-cell method based on the CFD-CAD integration, which can achieve the accurate representation of the geometry designed by a CAD tools. The technique is frequently satisfied, and it will be almost universally so in the future, as the CFD-CAD traffic increases.