• Journal of the Korean Vacuum Society
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• v.15 no.5
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• pp.518-526
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• 2006

Nanoporous alumina film was fabricated by anodization of an aluminum sheet. Highly ordered nanowellstructured and nanonets-tructured metal films were fabricated by vacuum evaporation of several metals(Al, Sn, and Co) using the anodic nanoporous alumina film as a template. In this experiment, an anodic porous alumina film with the cell size of 100 nm and the pore diameter of 60 nm was used. The resistance heating method was adopted for evaporating a desired metal, and vapor deposition was carried out under the base pressure of torr. It was founded that whether the structure fabricated by vacuum evaporation is nanowell or nanonet is dependent on the amount of deposited material. When an anodic porous alumina film with the cell size of 100 nm and the pore diameter of 60 nm was used, a nanowell-structured film was fabricated when a sufficient amount of metal was suppled to cover the surface pores. On the other hand, nanonet-structured film was fabricated bellow a half the amount of metal required for nanowell-structured film.

• Korean Journal of Crystallography
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• v.11 no.1
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• pp.22-27
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• 2000

The structure of cis-(malonato)[(4R,5R)-4,5-bis(aminomethyl)-2-isopropyl-1,3-dioxolane]platinum(II) with a potent anticancer activity has been determined by the X-ray crystallographic method. Crystal data are as follows: Pt(C/sub 11/H/sub 20/N₂O/sub 6/), M/sub 4/=471.38, monoclinic, P2₁, a=7.112(1), b=33.615(3), c=7.135(1)Å, β=116.80(1)°, V=1522.6(3)Å, and Z=4. The two independent molecules with very similar structures are approximately related by pseudo two-fold screw axis symmetry, which makes the monolinic cell look like the orthorhombic cell with one molecule in the asymmetric unit and space group C222₁. The crystal packing mode is similar to that of the analogue with the dimethyl substituents instead of the isopropyl group. The Pt atom is coordinate to two O and two N atoms in a square planar structure. The six-membered chelate ring in the leaving ligand assumes a conformation intermediate between the half chair and the boat forms. The seven-membered ring in the carrier ligand assumes a twist-chair conformation and the oxolane ring assumes an envelope conformation. Crystal packing consists of the extensive hydrogen-bonding network in the two-dimensional molecular layers and weak van der Waals interactions between these layers.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.1
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• pp.93-100
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• 2014

Steel reinforcement buried in concrete structure in submerged zone does not easily become corroded due to lack of dissolved oxygen. For that reason, accelerated corrosion test in submerged state is performed with an electrochemical method, which is not suitable for actual corrosion mechanism and makes it difficult to find relevance with long-term behavior. In this study, accelerated corrosion test was performed with the temperature and chloride concentration as main variables in order to establish a method for accelerated corrosion test in submerged zone. Corrosion was determined by the result of reinforcement corrosion monitoring based on galvanic potential measurement and half-cell potential method. The accelerated corrosion test result showed that temperature had the most dominant influence. To determine the chloride content, chloride concentration by depth in the test sample was measured. With the same conditions, chloride penetration interpretation was performed by DuCOM, a FEM durability interpretation program. Also, a test was performed to measure dissolved oxygen according to soaking conditions of artificial seawater, which was used for verifying the validity of the accelerated corrosion test result.

• The Korean Journal of Cytopathology
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• v.1 no.1
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• pp.1-17
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• 1990

Hepatocellular carcinoma (HCC) is malignant tumor frequently occurring in Koreans. There have been few reports regarding the cytologic findings of fine needle aspiration (FNA) of HCC. Most have suggested a diagnostic problem in the cytology distinguishing HCC from some benign hepatic lesions-for example, a regeneration nodule in cirrhosis and liver cell adenoma. In spite of its high frequency in Korea, no cytologic study has been reported, concerning the FNA of HCC. In an attempt to achieve cytologic criteria for the diagnosis of HCC, the authors studied retrospectively cytopathologic findings of 247 cases of HCC. These cases were confirmed either by histoiogic examination including lobectomy, biopsy, or ceil block material, or, when tissue diagnosis was unavailable, by a high serum alpha-fetoprotein level (over 400 I. U.). All aspiration smears were stained by the Papanicolaou method. In each case, the smears were analyzed for cell patterns and various cytomorphology of the tumor cells. The smear background was assessed for the presence of tumor cell necrosis and inflammatory components and compared to that of metastatic carcinomas. The cell patterns were classified as trabecular, acinar, dispersed, and irregular. The cytologic parameters analyzed included the degree of nuclear atypia and the presence of mitoses, intranuclear cytoplasmic inclusions, nucleolar prominency, endothelial lining, multinucleated giant cells, eosinophiic globules, bile, and Mallory body. Most of the FNA of HCC showed markedly cellular smears. The tumor cells were most frequently arranged in a trabecular pattern (80.3%). The irregular (12.6%), the acinar (5.5%), and the dispersed patterns (1.7%) followed in decreasing frequency. Individual hepatoma cells were larger than normal liver cells. However, they had morphologic features characteristic of the hepatic cells the cells were round or polygonal, their cytoplasm was abundant and granular with eosinophilic or amphophilic stainability, and their nuclei were round to oval, located centrally, and tended to have prominent nucleoli. Anaplasia and pleomorphism of tumor cells were generally mild to moderate. These findings existed even in very well differentiated cases. Mitotic figures were present in about 85% of the cases. Prominent nucleoli were observed only in about half the cases. The frequency of other cytologic features was as follows intranuclear cytoplasmic inclusion in 86.8% : endothelial lining in 56.1% : bile in 19.8% : and giant cells in 60.1%. Clear cells were often present in 11.7%, Most aspiration smears of HCC displayed clean background without necrosis or inflammatory material in contrast to the dirty, necrotic background of metastatic cancers and cholangiocarcinomas. Based on the above mentioned features, it is suqqested that the cytologic critieria most important for the diagnosis of HCC include a markedly cellular smear, trabecular pattern, hepatocytoid appearance of tumor cells, endothelial lining, the presence of bile, giant cells, intranuclear cytoplasmic inclusions, and prominent nucleoli, Among these, trabecular pattern, endothelial lining, giant cells and clean smear background are points to be considered in differentiating HCC from metastatic and cholangiocellular carcinoma.

• Journal of the Korean Ceramic Society
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• v.47 no.6
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• pp.638-642
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• 2010

The spinel material $Li_4Ti_5O_{12}$ has attracted considerable attention as an anode electrode material for many battery applications owing to its light weight and high energy density. However, the real capacity of $Li_4Ti_5O_{12}$ powder as determined by the solid-state method is lower than the ideal capacity. In this study, we investigated the effect of the dopants in M-doped spinel $Ba_xLi_{4-2x}Ti_5O_{12}$(x=0.005, 0.05, 0.1) powders prepared by the solid-state reaction method and used as the anode material in lithiumion batteries. The results confirmed the effect of the Ba and Sr dopants on the powder properties of the spinel $Li_4Ti_5O_{12}$, which exhibited a pure spinel structure without any secondary phase in its XRD pattern. Moreover, the electrochemical properties of the spinel M-LTO materials were investigated using a half cell. The electrochemical data show that cells with anodes made of undoped $Li_4Ti_5O_{12}$ and Ba- and Sr-doped $Li_4Ti_5O_{12}$ have discharge capacities of 97, 130, and 112 mAh/g, respectively, at the first cycle. Moreover, the Ba- and Sr-doped spinel $Li_4Ti_5O_{12}$ demonstrated good properties in the mid-voltage range at 1.55 V, showing stable cyclic voltammogram properties which surpassed those of the same material without Ba or Sr at 1 C after 100 cycles.

• Tuberculosis and Respiratory Diseases
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• v.47 no.5
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• pp.660-668
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• 1999

Background: Lung cancer continues to increase and one half of all cases of lung cancer occur in patients age 65 years and older. However, it seems that lung cancer is less treatable in elderly patients because of co-morbid illness or poor tolerance of surgery and chemotherapy. The intention of this study is to seek an adequate treatment approach for lung cancer in the elderly through an understanding of its characteristics. Method: The clinical data of 207 patients who were diagnosed with histologically proven lung cancer at the department of internal medicine in Seoul Municipal Boramae Hospital between September 1994 and August 1998 were retrospectively analyzed according to their age groups; group I$\geq$65 years(n=122) and group II<65 years(n=85). Results: The peak incidence of age was 7th decade(36.2%) and male age 65 years and older were 42% of all patients. Although dyspnea was more common in group I(26%) than in group II(11%)(p=.0l), there were no significant difference in other symptoms, stage, and histologic type between two groups. Group I significantly had more patients with poor performance(ECOG 3&4) than group II(35.2% vs.12.9%, p=.000). The percentage of patients with non-small cell carcinoma received supportive care only was significantly higher in group I than in group I(74% vs. 35%, p=.000). However, survival of patients who had curative intent treatment was similar between two groups(median survival 11.3 mos vs. 23 mos, p>.05). The histologic subtype, stage and performance status were significant prognostic factors affecting survival, but age itself was not. Conclusion : Lung cancer is prevalent in the elderly and aggressive diagnosis and treatment should be considered in elderly patients with good performance status.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.1
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• pp.1-8
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• 2009

EMMC(Entrapped Mixed Microbial Cell) process which is a kind of active cell immobilizing method was applied to treat fisheries processing wastewater biologically. Kinetic constants were calculated for organic and nitrogen removal and effect of effluent recycling on system performance was evaluated also. Yield coefficient, Y showed relatively low value compared with Y value obtained from conventional activated sludge process. It means that EMMC process can reduce amount of excess sludge significantly compared with conventional activated sludge process. Endogenous respiration coefficient $k_e$ of EMMC process also showed relatively low value compared with that of conventional activated sludge process. Yield coefficient Y, endogenous respiration coefficient $k_e$ and half saturation constant $k_s$ obtained from EMMC process in terms of nitrification were compared with reported value from literature based on suspended growth nitrification system. The value of Y obtained from this study has no difference compared with values obtained from literature review and $k_e$ of this study was low but $k_s$ of this study was high compared than values obtained from suspended growth nitrification system. To evaluate the effect of internal recycling on system performance, system was operated with internal recycling ratio of 1.5Q, 2.0Q, 2.5Q and 3.0Q. increase of internal recycling ratio effect more greatly on improvement of denitrification efficiency than that of nitrification efficiency. Accordingly, optimization of internal recycling ratio has to be based on improvement of anoxic reactor performance.

• Journal of Life Science
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• v.29 no.6
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• pp.724-734
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• 2019

The present study investigated the cytotoxicity of particulate matter (PM) derived from car air filter (outdoor PM) and home cleaner filter (indoor PM) in the various human cell lines. Each outdoor and indoor PM were harvested by ethanol extraction method, subsequently sieved with 10 um filter paper, sterilized with autoclave and added to culture media. The half maximal inhibitory concentration ($IC_{50}$) values was significantly (p<0.05) lower in the outdoor PM, compared with indoor PM, and the significantly (p<0.05) higher $IC_{50}$ values were observed in the cancer cell lines (A-549 lung adenocarcinoma and AGS stomach adenocarcinoma), than those of normal MRC-5 fibroblasts and dental papilla tissue derived-mesenchymal stem cells (DSC). After being exposed to $100{\mu}g/ml$ outdoor PM for 7 days, the population doubling time (PDT) was significantly (p<0.05) increased in especially MRC-5 and DSC cell lines, compared with untreated cell lines. Further, the expression of senescence-associated ${\beta}$-galactosidase activity was up-regulated in all the cells exposed to outdoor PM than those of untreated control. Besides, the expression level of inflammation-associated genes, such as cyclooxygenase-2 (COX-2) and interleukin-6 (IL-6) was found to be significantly (p<0.05) increased in the outdoor PM-treated cell lines than those of untreated cell lines. Our results showed that PM induces the cytotoxicity via arrest of cell growth, cell damage and inflammation response.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.33 no.6
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• pp.475-482
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• 2020

For electronic paper displays using electrophoresis, the response time and reflectivity of the image panel fabricated by filtering are analyzed. For the filtering process, a square wave and ramp wave are applied to white charged particles with a unique q/m value. We divide the sample panels into #1 to #4 according to the applied waveform in the filtering process. Step waves comprising two steps are used to drive the panel; therefore, we divide the driving conditions into D1~D4. The applied voltage at the first stage of the half cycle of the driving waveform moves the charged particles attached via the image force from the electrode, and the applied voltage at the second stage moves the floating charged particles by detaching. As mentioned, four types of driving conditions (D1 to D4) classified according to the half cycle of the driving waveform are applied to the samples #1 to #4), which are classified according to four types of filtering process. When driving condition D1 is applied to the four types of sample panels, the rise time of #1 is 1.59s, #2 is 1.706s, #3 is 1.853s, and #4 is 1.235s, resulting in #4 being relatively faster compared with other sample panels, and showing the same trend in other driving conditions. As a result, we confirm that applying the driving condition D1 causes abrupt movement of the white charged particles injected into the cell. When the same driving waveform (D1) is applied to each sample, reflectivities of 32.1% for #1, 31.4% for #2, 27.9% for #3, and 63.4% for #4 are measured. From the experiment, we confirm that the driving condition D1 (1s of 3.5 V, 9s of 3.0 V) and ramp wave #4 in filtering are desirable for good reflectivity and response time. Our research is expected to contribute to the improvement of the filtering process and optimization of the driving waveform.

• Journal of the Korea institute for structural maintenance and inspection
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• v.20 no.4
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• pp.136-143
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• 2016

There are various method for evaluating the durability life of concrete structures due to salt damage. The best way is to perform a corrosion test for a rebar embedded in concrete specimen was exposure to marine environment. However, this method has the disadvantage that it takes a long period of time. Also, accelerated corrosion test which was complemented complements the time-consuming weakness is limited to apply because it could not reveal a correlation between long-term exposure test. Accordingly, the purpose of this study is to derive a correlation coefficient between cycle drying-wetting accelerated corrosion test and long-term exposure test. Corrosion initiation time was measured in four types of concrete samples, i.e., two samples mixed with fly ash(FA) and blast furnace slag(BS), and the other two samples having two water/cement ratio(W/C = 0.6, 0.35) without admixture(OPC 60 and OPC 35). The accelerated corrosion test was carried out by two case, i.e., one is a cyclic drying-wetting method(case 1), and the other is a artificial seawater ponding test method(case 2). Whether corrosion occurs, it was measures using half-cell potential method. The results indicated that case 1 is to accelerated the corrosion of rebar about 24~36% as compared with case 2, then the corrosion of rebar embedded in concrete occurred according to the order of OPC60, FA, BS, OPC35. Correlation coefficient between accelerated corrosion test and long-term exposure test, case 1 is 4.23 to 5.42, and case 2 is 6.54 to 7.82.