• Journal of Advanced Marine Engineering and Technology
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• v.34 no.1
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• pp.92-101
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• 2010

Recently, the magnetic bearings which have many advantages such as no noise, less mechanical friction are widely applied to the suspension of rotors on the rotary machineries. However, the magnetic bearing system is inherently unstable, nonlinear and MIMO(multi-input-multi-output) system as well. In this paper, we design a state feedback controller using linear matrix inequality(LMI) to the multi-objective synthesis, for the magnetic bearing system with integral type servo system. The design objectives include $H_{\infty}$ performance, asymptotic disturbance rejection, and time-domain constraints on the closed-loop pole location. The results of computer simulation show the validity of the designed controller.

• The KSFM Journal of Fluid Machinery
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• v.19 no.3
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• pp.5-9
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• 2016

The purpose of this paper is to define criteria to be used as part of the engineering design for an oil sands plant equipped with the steam assisted gravity drainage process. In this effort, the oil treatment process of an oil sands plant on a pilot scale was focused for detailed investigation. The thermodynamic properties of the process fluid, which is mainly composed of bitumen and water, were estimated with the CPA model. The commercial tool aspen HYSYS was used for the analysis throughout this work along with the provided input data and some necessary assumptions. From the simulation results, the heat and mass balances for a 300 BPD plant were established in order to define standard data for its modular design. In particular, the basis of design for equipment size, heat transfer areas, capital cost and operation cost was extensively discussed.

• Biotechnology and Bioprocess Engineering:BBE
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• v.10 no.3
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• pp.180-185
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• 2005

Cytosine deaminase (cytosine aminohydrolase, EC 3.5.4.1) stoichiometrically catalyzes the hydrolytic deamination of cytosine and 5-fluorocytosine to uracil and 5-fluorouracil, respectively. Amino acid residues located in or near the active sites of the intracellular cytosine deaminase from chromobacterium violaceum YK 391 were identified by chemical modification studies. The enzymic activity was completely inhibited by chemical modifiers, such as 1mM NBS, chloramine-T, $\rho-CMB,\;\rho-HMB$ and iodine, and was strongly inhibited by 1mM PMSF and pyridoxal 5'-phosphate. This chemical deactivation of the enzymic activity was reversed by a high concentration of cytosine. Furthermore, the deactivation of the enzymic activity by $\rho-CMB$ was also reversed by 1mM cysteine-HCI, DTT and 2-mercaptoethanol. These results suggested that cysteine, tryptophan and methionine residues might be located in or near the active sites of the enzyme, while serine and lysine were indirectly involved in the enzymic activity. The intracellular cytosine deaminase from C violaceum YK 391 was assumed to be a thiol enzyme.

• The Korean Journal of Cytopathology
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• v.9 no.2
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• pp.233-239
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• 1998

Clear ceil sarcoma(CCS) is an uncommon soft tissue sarcoma that occurs in tendons and aponeuroses, usually of the lower extremities and is believed to be of neural crest origin that have a capability to produce melanin. These tumors commonly metastasize and have a very poor prognosis. The fine needle aspiration cytologic finding of CCS is not well documented. We recently experienced a case of CCS. The patient was a 54-year-old male with painful swelling of the right inguinal area. Fine needle aspiration cytology revealed polygonal or fusiform tumor cells with clear or granular cytoplasm and vesicular nuclei containing one or two nucleoli. Immunohistochemical staining for S-100 protein and HMB-45 revealed strong positivity and variable developing stages of premelanosomes were observed by electron microscopy in the excised specimen.

• Journal of Microbiology and Biotechnology
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• v.25 no.6
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• pp.880-886
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• 2015

Bacterial heme was produced from a genetic-engineered Escherichia coli via the porphyrin pathway and it was useful as an iron resource for animal feed. The amount of the E. coli-synthesized heme, however, was only few milligrams in a culture broth and it was not enough for industrial applications. To analyze heme biosynthetic pathways, an engineered E. coli artificially overexpressing ALA synthase (hemA from Rhodobacter sphaeroides) and pantothenate kinase (coaA gene from self geneome) was constructed as a bacterial heme-producing strain, and both the transcription levels of pathway genes and the intermediates concentrations were determined from batch and continuous cultures. Transcription levels of the pathway genes were not significantly changed among the tested conditions. Intracellular intermediate concentrations indicated that aminolevulinic acid (ALA) and coenzyme A (CoA) were enhanced by the hemA-coaA co-expression. Intracellular coproporphyrinogen I and protoporphyrin IX accumulation suggested that the bottleneck steps in the heme biosynthetic pathway could be the spontaneous conversion of HMB to coproporphyrinogen I and the limited conversion of protoporphyrin IX to heme, respectively. A strategy to increase the conversion of ALA to heme is discussed based on the results.

• Tuberculosis and Respiratory Diseases
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• v.48 no.5
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• pp.788-793
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• 2000

Tuberous sclerosis is a rare hereditary anomaly of variable penetrance characterized by mental retardation, epilepsy, and adenoma sebaceum. Pulmonary involvement is uncommon, but, when involved by tuberous sclerosis, it shows characteristic reticulonodular infiltration and cystic changes. Lymphangioleiomyomatosis is a rare disease of unknown cause that affects women of reproductive age. It is characterized by progressive proliferation of smooth muscle in the lung. We experienced one case of pulmonary lymphangioleiomyomatosis associated with tuberous sclerosis in a 26-year-old female patient. This case is reported with a brief review of the literature.

• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.375-381
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• 1995

Two intraocular tumors were identified in low and medium dosed groups of a carcinogenicity study using 200 males and 200 females Sprague-Dawley rats in Screening & Toxicology Research Center, Korea Research Institute of Chemical Technology. The tumors were grossly observed as white or yellow, unilateral nodules. They were approximately $1-2{\times}3-5mm$ in size. The tumors located in the region of iris and/or ciliary body invaded peripheral cornea. The microscopic features were usually composed of spindle cells arranged in parallel, forming gently curving bundles or whorls. The spindle cells had poorly defined cell boundaries, scant to moderate cytoplasm, fusiform nuclei and indistinct nucleoli. Mitotic figures were rare and areas of necrosis were present. The spindle cells had positive immunoreactivity for S-100 protein and vimentin but negative for desmin, collagen and HMB-45 antibody. In special histochemical studies, the spindle cells react with Gomori's stain for argyrophih fibers, Prussian blue stain for iron but negative with Masson-Fontana's stain for melanin granules. Ultrastructurally, cytoplasmic premelanosomes were not observed in the tumor cells due to the poor preservation of tumor masses. Based on the results, the tumors were diagnosed as amelanotic melanoma.

• Journal of Yeungnam Medical Science
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• v.16 no.1
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• pp.108-113
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• 1999

Clear cell sarcoma is a rare soft tissue sarcoma that occurs in tendons and aponeuroses, usually in the lower extremities in young adults. The exact histogenesis is not definitely established. We experienced a case of 58 year-old female who presented with a $3.2{\times}2.2cm$ sized mass located in the subcutaneous tissue of the left lower thigh. The mass was well-circumscribed, grayish and firm. Two small satellite nodules were also seen. Histrionically, the tumor was composed of round to fusiform cells with clear or pale eosinophilic cytoplasm and separated into compact nests or short fascicles by delicate fibrous septa. The melanin pigments and hemosiderin were seen. Tumor cells showed positive reaction for S-100 protein and HMB-45. The ultrastructural examination showed abundant mitochondria and melanosomes.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.44 no.1
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• pp.29-33
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• 2018

Sinonasal mucosal melanoma (SNMM) in the maxillary sinus is a rare disease condition. Compared to oral mucosal melanoma, SNMM has a bulky, exophytic, and polypoid appearance, is weakly pigmented, and associated with unspecific symptoms. Due to these features, SNMM in the maxillary sinus has been misdiagnosed as nasal polyps and chronic sinusitis. In this case report, we described SNMM occurring in the right maxillary sinus simulated as a cystic or benign lesion. Cortical bone thinning and expansion were observed around the mass. The excised soft mass was encapsulated and weakly pigmented. The mass was clearly excised and covered with a pedicled buccal fat pad graft. Diagnosis using immunohistochemistry with S-100 and homatropine methylbromide-45 (HMB-45) is critical for proper treatment.

• Korean Journal of Veterinary Pathology
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• v.2 no.1
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• pp.25-30
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• 1998

An in vivo model for human melanoma was established with the growth and metastasis of SK-MEL-2 cells. The tumor was introduced into C.B-17 SCID(severe combined immunodeficiency) mice intraperiotneally subcutaeously and intravenous inoculations. Tumors developed in 100% of mice inoculated subcutaneously and intraeritoneally both at site of inoculation and as metastatic tumor in the liver lungs and diaphragm. With intravenous inoculation 50% of mice showed metastasis in the spleen. Additionally metastatic foci that were not detected either by gross and/or standard histopathologic examination were demonstrated in the spleen and lungs by immunohistochemistry with HMB-45 monoclonal antibody. We conclude that the SCID mouse supports growth and metastasis of human malignant melanoma SK-MEL-2 cells.