• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.714-722
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• 1998

Background: Rifampicin (RFP) is a key component of the antituberculous short-course chemotherapy and the RFP resistance is a marker of multi-drug resistant (MDR) tuberculosis. RPoB gene encodes the $\beta$-subunit of RNA polymerase of M. tuberculosis which is the target of RFP. And the mutations of rpoB gene have been found in about 96% of rifampicin resistant clinical isolates of M. tuberculosis. So in order to find a rapid and clinically useful diagnostic method in identifying the RFP resistance, we compared the PCR -line probe method with PCR-SSCP for the detection of the rpoB gene mutation in cultured M. tuberculosis. Methods: 45 clinical isolates were collected from patients who visited Sung Kyun Kwan University Hospital. The RFP susceptibility test was referred to the referral laboratory of the Korean Tuberculosis Institute. 33 were rifampicin resistant and 12 were rifampicin susceptible. The susceptibility results were compared with the results of the PCR-BSCP and PCR-line probe method. Results: We could find rpoB mutations in 27/33(81.8%) RFP-resistant strains by PCR-line probe method, and in 23/33 (69.7%) by PCR-SSCP and there was no significant difference between two methods. There was no mutation in rifampicinn susceptible strains by both methods. Conclusion: PCR-line probe method would be a rapid, sensitive and specific method for the detection of rifampicin resistant Mycobacterium tuberculosis.

• Tuberculosis and Respiratory Diseases
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• v.40 no.4
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• pp.395-403
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• 1993

Background: The cell cycle is composed of a series of steps which can be negatively or positively regulated by various factors. Alteration or inactivation of p53 by mutations, or by its interactions with oncogene products of DNA tumor viruses, can lead to cancer. Mutations of the p53 gene occur frequently in human primary lung cancers and the wild-type p 53 allele is often concomitantly deleted. These suggest that deprivation of suppressive role of the wild-type p53 may ensure tumor cell growth presumable by the mutant p53 gene. Methods: In an attempt to investigate this hypothesis, a mutant p53 gene was immunohistochemically demonstrated in the formalin-fixed paraffin-embedded tissue sections of lung cancers by using a monoclonal antibody p53 (Ab-3 and clone DO7). Results: The expression of p53 (DO7) was found in all four normal lung tissues, four small cell carcinomas, and four non small cell carcinomas in histologic types of lung cancer. In the six normal lung tissues the expressions of p53 (Ab-3) were not found. Contrarily, the expression of p53 (Ab-3) was found in the nuclei of lung cancers among fifteen (46.9%) of thirty-two cases studied. The expression of p53 (Ab-3) was disclosed in three case (37.5%) of eight small cell carcinomas and twelve cases (50.0%) of twenty-four non small cell carcinomas in histologic types of lung cancer. Conclusion: These findings suggest that expression of the mutant p53 is related to the one of events in the pathogenesis of human lung cancer and the role of the other oncogenes might be also related to the development of lung cancers.

• Tuberculosis and Respiratory Diseases
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• v.47 no.4
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• pp.478-487
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• 1999

Background : Differential diagnosis of pleural malignant mesothelioma from secondary metastatic adenocarcinoma is often difficult. A variety of pathologic techniques have been developed to make a differential diagnosis of carcinoma from mesothelioma. Immunohistochemistry detecting diverse antigenic substances such as CEA, Leu-M1, Bn-3, S-100 protein, vimentin, CK and EMA has been claimed to be of value as a panel in the differential diagnosis of adenocarcinoma from mesothelioma. The aim of this study was to investigate the suitable antibodies to distinguish mesothelioma from metastatic adenocarcinoma and establish candidate markers in a panel. Methods : Complete, one-hour immunohistochemical staining using antibodies against cytokeratin (CK), epithelial membrane antigen(EMA), S-100 protein, vimentin, B72-3, Leu-M1, and carcino-embryonic antigen(CEA) was applied to cell blocks from 7 mesotheliomas and 7 adenocarcinomas which were confirmed by electron microscopic and histpathologic methods. Results : All adenocarcinomas and 71.4% of mesotheliomas expressed the cytokeratin and EMA. S-100 protein and vimentin were expressed in 57.1% and 42.9% of mesotheliomas and 14.3% and 28.5% of adenocarcinomas, respectively. B72-3 was expressed in all adenocarcinomas, but in none of mesotheliomas. Leu-M1 was positive in 71.4% of the adenocarcinoma and 14.3% of the mesotheliomas. CEA was positive in all adenocarcinomas and 42.9% of mesotheliomas. Leu-M1 and B72-3 were coexpressed in 71.4% of adenocarcinomas but in none of mesothelioma. B72-3 and CEA were coexpressed in all adenocarcinomas, but in none of mesotheliomas. Conclusion : We concluded that B72-3 immunohistochemistry or panel staining of B72-3 and CEA could be recommanded for the differential diagnosis of pleural mesothelioma from metastatic adenocarcinoma.

• Tuberculosis and Respiratory Diseases
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• v.43 no.6
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• pp.925-935
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• 1996

Background : In order to elucidate one of the pathogenic mechanisms of ARDS associated with pulmonary surfactant and oxidant injury, acute lung injury was induced by N-nitroso N-methylurethane (NNNMU). In this model, the role of phospholipase $A_2$ ($PLA_2$), surfactant, gamma glutamyl transferase (GGT) and morphology were investigated to delineate one of the pathogenic mechanisms of ARDS by inhibition of $PLA_2$ with high dose of dexamethasone. Method: Acute lung injury was induced in Sprague-Dawley rats by NNNMU which is known to induce acute lung injury in experimental animals. To know the function of the alveolar type II cells, GGT activity in the lung and bronchoalveolar lavage was measured. Surfactant phospholipid was measured also. $PLA_2$ activity was measured to know the role of $PLA_2$ in ARDS. Morphological study was performed to know the effect of $PLA_2$ inhibition on the ultrastructure of the lung by high dose of dexamethasone. Results : Six days after NNNMU treatment (4 mg/kg), conspicuous pulmonary edema was induced and the secretion of pulmonary surfactant was decreased significantly. In the acutely injured rats' lung massive infiltration of leukocytes was observed. At the same time rats given NNNMU had increased $PLA_2$ and GGT activity tremendously. Morphological study revealed bizarre shaped alveolar type II cells and hypertrophied lamellar bodies in the cytoplasm of the alveolar type II cells. But after dexamethasone treatment (20 mg/kg, for six days) in NNNMU-treated rats, these changes were diminished i.e. there were decrease of pulmonary edema and increase of surfactant secretion from alveolar type D cells. Rats given dexamethasone and NNNMU had decreased $PLA_2$ and GGT activity in comparison to NNNMU induced ARDS rats. Conclusion : Inhibition of $PLA_2$ by high dose of dexamethasone decreased pathological findings caused by infiltration of leukocytes and respiratory burst. Based on these experimental results, it is suggested that an activation of $PLA_2$ is the one of the major factors to evoke the acute lung injury in NNNMU-induced ARDS rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.30 no.6
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• pp.1253-1259
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• 2001

The purpose of this study was to investigate the effects of green tea catechin on change of bone tissue in long-term cadmium treated rats. Sprague-Dawley male rats weighing 100$\pm$10 g were randomly assigned to one normal group and three cadmium treated groups. Cadmium groups were classified to catechin free diet group (Cd-0C group), 0.25% catechin diet group (Cd-0.25C group) and 0.5% catechin diet group (Cd-0.5C group) according to the levels of catechin supplement. Animals were raised for 20 weeks. Cadmium were supplied as drinking water of 50 ppm Cd$^{2+}$. Effects of catechin were analyzed on changes of bony tissue in long-term cadmium treated rats by determining the accumulated cadmium in bone and bone mineral density and micro- photographs of bony tissue. The cadmium accumulation of tibia and femur were higher in Cd-treated groups than in normal group, but they was lowered by catechin supplementation. The bone mineral density (BMD) of tibia and femur in Cd-0C group was significantly lower than in normal group, but it of catechin supplemetation group was similar to normal group. Microphological changers were appeared under a light microscope and an electro microscope reveal no structural changes in bony spicules, marrow cell distribution and cellular morphology in all groups. The bone weight and length tend to decrease in Cd-0C groups. Catechin supplementation in long-term cadmium treated rats depressed the cadmium accumulation in bony tissue that led to improve the bone mineral density in tibia and femur.r.

• Journal of Hydrogen and New Energy
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• v.10 no.2
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• pp.119-130
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• 1999

After preparing $Mg_2Ni_{1-x}{^{57}}Fe_x$(x=0.015, 0.03, 0.06, 0.12 and 0.24) alloys, they were studied by $M{\ddot{o}}ssbauer$ resonance. The $M{\ddot{o}}ssbauer$ spectra of x=0.015 and 0.03 alloys exhibit two doublets (doublet 1, 2). That of x=0.06 alloys shows two doublets (doublet 1,2) and one six-line, and those of x=0.12 and 0.24 alloys have only one six-line. The doublet 1 for x=0.015, 0.03 and 0.06 alloys is considered to result from a fraction of Fe in excess showing a superparamagnetic behavior. The doublet 2 is considered to result from the Fe substituted for Ni in the $Mg_2Ni$ phase. The values of isomer shift 0.24 ~ 0.28 mm/s suggest that the iron exist in the state $Fe^{+3}$. The result that the quadrapole splitting of the doublet 2 is not zero shows that the distribution of electrons around the iron is asymmetric. Their values for the doublet 2, 1.20 ~ 1.38 mm/s, approach the value of quadrapole for the oxidation number +3. The six-line showing the magnetic hyperfine interactions results from the iron which has not substituted the nickel in the $Mg_2Ni$ phase. The $M{\ddot{o}}ssbauer$ spectra of the hydrided alloys with x=0.015 and 0.03 show six-line. This suggests that the iron segregates with the hydriding reaction. The analysis results of the $M{\ddot{o}}ssbauer$ spectrum, the variation of magnetization with magnetic field, Auger electron spectroscopy and electron diffraction show the segregation of Ni and the formation of MgO. This is considered to result from the reaction of the $Mg_2Ni$ phase with the oxygen contained in the hydrogen as impurity.

• Journal of Intelligence and Information Systems
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• v.22 no.4
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• pp.157-176
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• 2016

For a long time, mobile phone had a sole function of communication. Recently however, abrupt innovations in technology allowed extension of the sphere in mobile phone activities. Development of technology enabled realization of almost computer-like environment even on a very small device. Such advancement yielded several forms of new high-tech devices such as smartphone and tablet PC, which quickly proliferated. Simultaneously with the diffusion of the mobile devices, mobile applications for those devices also prospered and soon became deeply penetrated in consumers' daily lives. Numerous mobile applications have been released in app stores yielding trillions of cumulative downloads. However, a big majority of the applications are disregarded from consumers. Even after the applications are purchased, they do not survive long in consumers' mobile devices and are soon abandoned. Nevertheless, it is imperative for both app developers and app-store operators to understand consumer behaviors and to develop marketing strategies aiming to make sustainable business by first increasing sales of mobile applications and by also designing surviving strategy for applications. Therefore, this research analyzes consumers' mobile application usage behavior in a frame of substitution/supplementary of application categories and several explanatory variables. Considering that consumers of mobile devices use multiple apps simultaneously, this research adopts multivariate probit models to explain mobile application usage behavior and to derive correlation between categories of applications for observing substitution/supplementary of application use. The research adopts several explanatory variables including sociodemographic data, user experiences of purchased applications that reflect future purchasing behavior of paid applications as well as consumer attitudes toward marketing efforts, variables representing consumer attitudes toward rating of the app and those representing consumer attitudes toward app-store promotion efforts (i.e., top developer badge and editor's choice badge). Results of this study can be explained in hedonic and utilitarian framework. Consumers who use hedonic applications, such as those of game and entertainment-related, are of young age with low education level. However, consumers who are old and have received higher education level prefer utilitarian application category such as life, information etc. There are disputable arguments over whether the users of SNS are hedonic or utilitarian. In our results, consumers who are younger and those with higher education level prefer using SNS category applications, which is in a middle of utilitarian and hedonic results. Also, applications that are directly related to tangible assets, such as banking, stock and mobile shopping, are only negatively related to experience of purchasing of paid app, meaning that consumers who put weights on tangible assets do not prefer buying paid application. Regarding categories, most correlations among categories are significantly positive. This is because someone who spend more time on mobile devices tends to use more applications. Game and entertainment category shows significant and positive correlation; however, there exists significantly negative correlation between game and information, as well as game and e-commerce categories of applications. Meanwhile, categories of game and SNS as well as game and finance have shown no significant correlations. This result clearly shows that mobile application usage behavior is quite clearly distinguishable - that the purpose of using mobile devices are polarized into utilitarian and hedonic purpose. This research proves several arguments that can only be explained by second-hand real data, not by survey data, and offers behavioral explanations of mobile application usage in consumers' perspectives. This research also shows substitution/supplementary patterns of consumer application usage, which then explain consumers' mobile application usage behaviors. However, this research has limitations in some points. Classification of categories itself is disputable, for classification is diverged among several studies. Therefore, there is a possibility of change in results depending on the classification. Lastly, although the data are collected in an individual application level, we reduce its observation into an individual level. Further research will be done to resolve these limitations.

• Korean Chemical Engineering Research
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• v.44 no.2
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• pp.179-186
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• 2006

Two types of $TiO_2$, nanotube and nanoparticle, were used for the mesoporous coatings by doctor blade technique followed by calcining at $450^{\circ}C$. The coatings were used as working materials for dye-sensitized solar cells (DSCs) later on and their photovoltaic characterization was carried out. The nanoparticle was synthesized from hydrogen titanate nanotube by hydrothermal treatment at $180^{\circ}C$ for 24 hr. The solar energy conversion efficiency (${\eta}$) of DSCs prepared by this nanoparticle reached 8.07％ with $V_{OC}$ (open-circuit potential) of 0.81 V, $I_{SC}$ (short-circuit current) of $18.29mV/cm^2$, and FF (fill factor) of 66.95％, respectively. For the preparation of nanotube, the concentration of NaOH solution varied from 3 M to 5 M. In the case of DSCs fabricated with nanotubes from 3 M NaOH solution, the ${\eta}$ reached 6.19％ with $V_{OC}$ of 0.77 V, $I_{SC}$ of $12.41mV/cm^2$, and FF of 64.49％, respectively. On the other hand, in the case of 5 M solution, the photovoltaic ${\eta}$ was decreased with 4.09％ due to a loss of photocarriers. In conclusion, it is demonstrated that the solar energy conversion efficiency of DSCs made from $TiO_2$ nanoparticle showed best results among those under investigation.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.2
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• pp.139-147
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• 2005

The efficacy of extraction from Inonotus obliquus was examined from the points of antioxidative characteristics and some antioxidative compounds. To enhance the efficient extraction for the effective components from Inonotus obliquus, temperature-stepwise water extraction method was applied. Temperature-stepwise water extracts were prepared for 8 hrs as follows: the first extract at 8$0^{\circ}C$, the second extract from the residue of the first extract at 10$0^{\circ}C$, and the third extract from the residue of the second extract at 12$0^{\circ}C$. Antioxidativeactivities were determined by electron-donating ability of DPPR - free radical, scavenging ability of ABTS$.$$^{+}$radical cation, and by inhibiting ability of linoleic acid autoxidation. In results, the first extract showed the least antioxidant capacity, and the third extract showed the highest antioxidant capacity. The third extract also had the greatest amounts of phenolic compounds and flavonoids. Amounts of phenolic compound from each extract were almost proportional to the radical scavenging activities and linoleic acid autoxidation inhibiting ability (r=0.960∼0.980, regression analysis). Furthermore, the effect of the pooled extract of all three extractions of Inonotus obliquus on the lipid peroxidation reacted with active oxygen species (KO$_2$, $H_2O$$_2$, $.$OH) and metals (Fe$^{2+}$, CU$^{2+}$) was evaluated by measuring the formation of thiobarbituric acid reactive substances (TBARS). The pooled Inonotus obliquus extracts lowered the amounts of TBARS formed by all of the active oxygen species and metals. Especially, these lowering effects were pronounced in the reaction with $.$OH and Fe$^{2+}$. These results suggest that the pooled temperature-stepwise extract from Inonotus obliquus could be potential functional materials to reduce the oxidation of lipids and other compounds induced by free radicals.adicals.

• Korean Chemical Engineering Research
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• v.45 no.6
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• pp.566-572
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• 2007

Two hybrid catalysts for the direct synthesis of DME were prepared and the catalytic activity of these catalysts were investigated. The hybrid catalyst for the direct synthesis of DME was composed as the catalytic active components of methanol synthesis and dehydration. The methanol synthesis catalyst was formed from the precursor contained Cu and Zn, the methanol dehydration catalyst was used ${\gamma}-Al_2O_3$. As PM-CZ+D and CP-CZA/D, Two hybrid catalysts were prepared by physical mixing method (PM-CZ+D) and precipitation method (CP-CZA/D), respectively. PM-CZ+D was prepared by physically mixing methanol synthesis catalyst and methanol dehydration catalyst, CP-CZA/D was prepared by depositing Cu-Zn or Cu-Zn-Al components on ${\gamma}-Al_2O_3$. The crystallinity and the surface morphology of synthesized catalyst were analyzed by X-ray diffraction (XRD) and scanning electron microscope (SEM) to investigate the physical property of prepared catalyst. And BET surface area by $N_2$ adsorption and the surface area of Cu by $N_2O$ chemisorption were investigated about the hybrid catalysts. In addition, catalytic activity of these hybrid catalysts was examined with varying reaction conditions. At that time, the reaction temperature of $250{\sim}290^{\circ}C$, the reaction pressure of 50~70 atm, the $[H_2]/[CO]$ mole ratio of 0.5~2.0 and the space velocity of $1,500{\sim}6,000h^{-1}$ were investigated the catalytic activity. From these results, it was confirmed that the reactivity of CP-CZA/D was higher than that of PM-CZ+D. When the conditions of reaction temperature, pressure, $[H_2]/[CO]$ ratio and space velocity were $260^{\circ}C$, 50 atm and 1.0, $3,000h^{-1}$ respectively, CO conversion using CP-CZA/D hybrid catalyst was 72% and the CO conversion of CP-CZA/D was more than 20% compared with the CO conversion of PM-CZ+D. It was known that Cu surface area of CP-CZA/D hybrid catalyst was higher than that of hybrid PM-CZ+D catalyst using $N_2O$ chemisorption. It was assumed that the catalytic activity was improved because Cu particle of hybrid catalyst prepared by precipitation method was well dispersed.