• The Korean Journal of Cytopathology
• /
• v.1 no.2
• /
• pp.179-184
• /
• 1990

Bone metastasis of hepatocellular carcinoma appears to be peculiar when clinical manifestation of liver disease is not apparent, and initial diagnosis of metastatic hepatocellular carcinoma by fine needle aspiration cytology is rarely obtained. We experienced a case of 45-year-old man with metastatic hepatocellular carcinoma in the sacrum, which was diagnosed by fine needle aspiration cytology. The intrahepatic mass, measuring 1.2 cm in diameter and kept unchanged in size for two years, was never proved to be hepatocellular carcinoma histopathologically. The aspirated neoplastic cells were mostly in sheets, showing abundant acidophilic cytoplasm and large, round, centrally located nuclei with single, prominent acidophilic mucleoli. In the cell block section, diagnosis of metastatic well-differentiated hepatocellular carcinoma was made without difficulty, and definite trabecular fashion with sinusoidal endothelial cell lining was found.

• Molecular & Cellular Toxicology
• /
• v.5 no.3
• /
• pp.243-249
• /
• 2009

Melamine, which is used to produce melamine resin for various industrial applications, has a high nitrogen content by mass. For this reason, it has been illegally added to foods to increase their apparent protein content. In the present investigation, melamine-induced oxidative damage of human lymphocyte DNA was evaluated by Comet assay. The in vitro oxidative DNA damage caused by melamine increased in a dose-dependent manner. This DNA damage was significantly inhibited by treatment with ascorbate. Moreover, the traditional Korean medicinal herb, named Acanthopanax, red ginseng and green tea markedly reduced the DNA damage. Various edible plant extracts also inhibited melamine-induced oxidative DNA damage in vitro. Melamine enhanced intracellular ROS generation, and this effect was suppressed by treatment with various antioxidants.

• Biomedical Science Letters
• /
• v.8 no.4
• /
• pp.245-250
• /
• 2002

Fibrinolytic enzyme has been purified from the edible mushroom, Tricholoma sejunctum using DEAE-cellulose chromatography, Phenyl-Sepharose chromatography and Mono-S column chromatography. The apparent molecular mass of purified enzyme was estimated to be 17100 Da by SDS-polyacrylamide gel electrophoresis and 19000 Da by gel filtration, Indicating that it was a monomer. The N-terminal amino acid sequence of the enzyme was Ala-Thr-Tyr-Lys-Ile-X-Ser-Ala-Thr-His-Gln-X-X-Leu-Val. It has a pH optimum at pH 9.5, suggested that purified enzyme was a alkaline protease. The activity of purified enzyme was inhibited by EDTA and 1,10-phenanthroline, indicating that purified enzyme is a metalloprotease. The activity of purified enzyme was increased by Zn$^{2+}$ and Co$^{2+}$, however, the enzyme activity was totally inhibited by Hg$^{2+}$.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2002.05a
• /
• pp.67-70
• /
• 2002

This paper presents the property of the Squeeze Film Damper (SFD) using Magneto-Rheological fluid (MR fluid). The damping property of a SFD for a flexible rotor system varied according to vibration mode. MR fluid is known as a functional fluid with controllable apparent viscosity of the fluid by applied magnetic field strength. When the MR fluid is applied in the SFD, the SFD using MR fluid can effectively reduce vibrations of the flexible rotor in a wide range of rotating speed by control of the applied magnetic field strength. To investigate in detail the SFD using MR fluid, the SFD to support one mass was constructed and its performance was experimentally investigated in the present study. The damping property of the SFD using MR fluid has viscous damping by Newtonian fluid, but not Coulomb friction by Bingham fluid. Therefore, The system damped by the SFD can be considered as a linear system.

• Journal of Mechanical Science and Technology
• /
• v.19 no.5
• /
• pp.1087-1094
• /
• 2005

This paper presents the validity and limitation of the thin-shell approach for the analysis of elastic wave propagation in a pipe with nonviscous liquid. The phase velocities calculated by the thin-shell approach were compared with those calculated by the thick-cylinder approach. In contrast to the case of the empty pipe, where only two modes were obtained and the first mode was calculated in a limited frequency range, the results for the liquid-filled pipe exhibits a large number of modes due to the large number of branches of the apparent liquid mass. Several of the lowest modes of the waves in a liquid-filled pipe were calculated for various pipe thicknesses in a low frequency range. The thin-shell approach was valid for a reasonable range of pipe thicknesses.

• Magazine of the Korean Society of Agricultural Engineers
• /
• v.43 no.6
• /
• pp.154-162
• /
• 2001

This study was performed to examine the rice growth and nutrient change in paddy soil with reclaimed sewage irrigation. Total nitrogen and total phosphorus in the experimental system were analyzed before and after rice culture. The experiment lasted three consecutive years, and this paper presents results of the last year. Additional supply of nutrients to the rice culture by reclaimed sewage irrigation was significant and it increased the yield. Nutrient uptake by rice plant increased with more nutrient supplied, however. there was limit in plant uptake. Nutrient accumulation occurred in the soil and it was more apparent for the phosphorus where most of the remaining quantity was accumulated while substantial amount of nitrogen was lost during the growing season. This study suggested that additional nutrient supply by reclaimed sewage irrigation might be a supplemental benefit to the rice culture, and it can help the fertilization management. However, long term effects of continual reclaimed sewage irrigation should be assessed carefully including nutrient mass balance in the paddy rice culture system.

• Advances in pediatric surgery
• /
• v.6 no.2
• /
• pp.134-138
• /
• 2000

Solid and papillary cystic neoplasm of pancreas is an uncommon low grade malignant tumor. It is predominant in young female between the second and third decades of life, and amenable to cure by surgical treatment. The authors report two cases of solid and papillary neoplasm of pancreas pathologically verified at Kyung Hee University Hospital. The first case was an 11-years old female patient and the other case was a 12-years old male. Symptoms were abdominal discomfort, nausea and vomiting in both cases and abdominal pain in the female patient. CT finding included a solid and papillary neoplasm of pancreas. The mass was well-demarcated with solid and cystic necrosis components. In the female patient, a large hematoma was found. Gross findings revealed apparent encapsulation, cystic degeneration and hemorrhagic necrosis. Microscopically the tumors were characterized by distinctive solid and papillary patterns of cellular arrangement without local invasion. Both patients were discharged after surgery and followed up without any problem.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2005.07a
• /
• pp.496-498
• /
• 2005

We reported that high dielectric hafnium oxide nano-film deposited by thermal atomic layer deposition on the poly-silicon film (poly-Si). The poly -Si film was produced by plasma enhanced chemical vapor deposition and excimer laser annealing. We used the hafniu m chloride ($HfCl_4$) and water as the precursors and analyzed the hafnium oxide film by transmission electron microscope and secondary ion mass spectrometer. Hafnium oxide produced by the ALD method showed very good coverage on the rough surface of poly-Si film. While deposited with 200 cycles, these hafnium oxide films revealed a relatively smooth surface and good uniformity, but the cumulative roughness produced by the incomplete reaction was apparent when the amount of deposition cycle increased to 600 cycles.

• Journal of the Korean Ceramic Society
• /
• v.26 no.4
• /
• pp.539-549
• /
• 1989

Polycrystalline TiO2 thin films were deposited on Si and Al2O3 substrates by CVD method. Ethyl titanate, Ti(OC2H5)4, was used as a source material for Ti and O, and Ar was used for carrier gas. In the surface chemical reaction controlled deposition condition, the apparent activation energy of 6.74 Kcal/mole was obtained, and the atomic adsorption on substrate surface was proved to be governed by Rideal-Elley mechanism. In the mass transfer controlled deposition condition, the deposition rate was in a good agreement with the result which was calculated by the simple boundary layer theory. It was also observed that TiO2 thin films show different surface morphology according to the different deposition mechanism, which was fixed by deposition conditions. This phenomenon could be well explained by the surface perturbation theory.

• 한국연소학회:학술대회논문집
• /
• 1998.10a
• /
• pp.1-8
• /
• 1998

Waste combustion above a grate is the core process of incineration systems, stability of which should be guaranteed for emission minimization. However, complicated reactions and heat and mass transfer phenomena make understanding the process difficult. One dimensional bed combustor with a numerical combustion model is utilized to investigate the combustion process of the bed, using cubic wood particles as a simulated fuel. Bed combustion behavior is characterized with apparent flame propagation speed, which has close relationship with air supply rate and chemical and physical characteristics of the fuel. Base on the availability of oxygen, two distinct reaction zone is identified; the oxygen-limited and the reaction-limited zone leading to the extinction by excessive convection cooling. The numerical modeling shows good agreement with the experimental results. The transient bed combustion behavior of local temperature and oxygen consumption rate is adequately reproduced. The numerical model is extended to model the waste bed combustion of a commercial incineration plant, which shows meaningful results as well.