• Journal of Life Science
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• v.19 no.8
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• pp.1023-1032
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• 2009

Despite the fact that many cancer cells are sensitive to TNF-related apoptosis-inducing ligand (TRAIL)-induced apoptosis, some cancer cells show either partial or complete resistance to TRAIL. Human leukemic K562 and CEM cells also show resistance to TRAIL-induced apoptosis. Novel molecular target and treatment strategies are required to overcome TRAIL resistance of human leukemia cells. Therefore, the purpose of this study was to target key anti-apoptotic molecules deciding TRAIL resistance for sensitization of TRAIL-resistant K562 and CEM cells, and to evaluate the effect of quercetin as a TRAIL sensitizer on these TRAIL-resistant cells. We found that quercetin acted in synergy with TRAIL to enhance TRAIL-induced apoptosis in K562 cells by inhibition of the DNA-PK/Akt signaling pathway, which leads to enhancement of TRAIL-mediated activation of caspases and concurrent cleavage of PARP and up-regulation of Bax. The findings suggest that the DNA-PK/Akt signaling pathway plays an essential role in regulating cells to escape from TRAIL-induced apoptosis, and quercetin could act in synergy with TRAIL to increase apoptosis by inhibition of the DNA-PK/Akt signaling pathway, which overcomes TRAIL-resistance of K562 and CEM cells. This study suggests that DNA-PK might interfere with TRAIL-induced apoptosis in human leukemic cells through activation of the Akt signaling pathway.

• Tuberculosis and Respiratory Diseases
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• v.49 no.2
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• pp.246-252
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• 2000

Lymphangioleiomyomatosis(LAM) is a rare disease of unknown etiology that occurs mainly in woman in her reproductive age. We recently experienced two cases of bilateral diffuse cystic lesion of the lung on chest X-ray and HRCT. The first case, a 26-year-old female, who had been diagnosed with tuberous sclerosis by the presence of clinical manifestation such as mental retardation, bilateral renal angiomyolipoma, adenoma sebaceum and generalized seizure, was admitted due to a recently developed hemoptysis. Chest PA showed diffuse ground-glass opacity with radiolucent cystic lesions of various sizes on both lung fields. HRCT showed innumerable small cystic lesions with suspicious diffuse ground-glass opacity on both lung fields The second case, a 30-year-old fema1e was admitted due to dyspnea and spewing of blood-tinged sputum for 2 weeks, shortly after delivery. Chest PA showed diffuse reticular and ground-glass opacities on both lung field. HRCT showed multiple well-defined and relatively uniform size air cysts with a uniform wall thickness on entire both lung fields, with small amount of right pleural effusion. By thoracoscopic lung biopsy she was diagnosed with pulmonary lymphangioleiomyomatosis. We report these cases with a brief review of the literatures.

• Journal of dental hygiene science
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• v.16 no.1
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• pp.18-25
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• 2016

The purpose of this study was to investigate a reliability and validity of the Korean version for measuring tool the job embeddedness of dental hygienists. The survey was modified and revised to fit into Korean culture. A survey was conducted with 274 dental hygienists in dental clinics. The data was used for the analysis of the study, using PASW Statistics 18.0 and IBM SPSS AMOS 7.0. The factor analysis showed that the job embeddedness of the dental hygienists was composed of three elements, namely 'organization fit', 'job connectivity', and 'personnel relationships'. The validity of the model examined by a confirmatory factor analysis satisfied most of the relevant requirements. All of the factors had the conceptual reliability and variant extracted index above the minimum requirements, ensuring reliability and concentrated validity. The Cronbach's alpha shows a good reliability. In conclusion, it was proven that dental hygienist's job embeddedness measurement tool has high validity and reliability. Further, this study could be used to improve dental hygienist's long term working, and the growth stage of dental clinic.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.610-617
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• 1995

Sleep apnea occurs in approximately 50% of patients with acromegaly, and sleep apnea is associated with increased cardiovascular diseases and mortality. In view of these findings, sleep apnea may be a factor in the increased incidence of cardiovascular deaths in acromegaly patients. We experienced a case of active acromegaly patient, 54-yr-old man, associated with obstructive sleep apnea syndrome, congestive heart failure with dilated cardiomyopathy and serious cardiac arrhythmias. He was treated for obstructive sleep apnea syndrome, diagnosed by overnight polysomnography, with nasal continuous positive airway pressure(CPAP) for 4 months, which successfully controlled his loud snoring, sleep apnea, nocturnal hypoxemia and apnea-related symptoms. And also he was treated for underlying acromegaly and cardiac complications with bromocriptine and cardiogenic drugs for 4 months, but still had elevated growth hormone(GH) and insulin like growth factor-1(IGF-1) levels and serious cardiac arrhythmias. We describe our experience about the effect of CPAP treatment in an active acromegaly patient associated with obstructive sleep apnea syndrome and cardiac complications with review of literature.

• Journal of Life Science
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• v.22 no.10
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• pp.1277-1285
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• 2012

The tumor necrosis, factor-related, apoptosis-inducing ligand (TRAIL) is regarded as a potentially useful anticancer agent with excellent selectivity for cancer cells. However, a considerable number of cancer cells are resistant to apoptosis induction by TRAIL. Developing strategies to overcome this resistance are important for the successful use of TRAIL for cancer therapy. Here, we revealed that siRNA-mediated downregulation of SIRT1 or SIRT1 inhibitor Amurensin G upregulated DR5 and c-Myc and downregulated c-$FLIP_{L/S}$ and Mcl-1, which was associated with sensitization of TRAIL-resistant MCF-7 cells to TRAIL. This result was followed by the activation of caspases, PARP cleavage, and downregulation of Bcl-2 in both TRAIL-treated MCF-7 cells transfected with SIRT1 siRNA and cells co-treated with Amurensin G and TRAIL. Our results suggest that the induction of DR5 and downregulation of c-FLIP via suppression of SIRT1 expression may be a useful strategy to increase the susceptibility of TRAIL-resistant cancer cells to TRAIL-induced cell death.

• Membrane Journal
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• v.25 no.5
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• pp.373-384
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• 2015

In the past few decades, polymeric membrane has played an important role in gas separation applications. For the separation of $CO_2$, one of greenhouse gases, high permselectivity, long-term stability and scale-up are needed. However, conventional polymeric membranes have shown a trade-off relation between permeability and selectivity while inorganic materials are highly permeable but expensive. Mixed matrix membranes (MMMs) combining the advantages of both polymeric and inorganic materials have become a possible breakthrough for the next-generation gas separation membranes. The MMMs could be either symmetric or asymmetric but the latter is more preferred to improve the permeance. Important factors influencing the MMM fabrication include homogeneous distribution of inorganic particles and good interfacial contact between inorganic filler and organic matrix. Recently, metal organic frameworks (MOFs) have received much attention as a new class of porous crystalline materials and a potential candidate for $CO_2$ separation. Zeolitic imidazolate frameworks (ZIFs), a sub-branch of MOFs, are the most widely used in MMMs due to small particle size and appropriate pore size for $CO_2$ separation. One of the major issues associated with the incorporation of porous particles in a polymeric membrane is to control the microstructure of the porous particle materials such as particle size, orientation, and boundary conditions etc. In this review, major challenges surrounding MMMs and the strategies to tackle these challenges are given in detail.

• Journal of Life Science
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• v.26 no.7
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• pp.826-834
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• 2016

The present investigation was undertaken to examine the effectiveness of the combination treatment of an Hsp90 inhibitor and a SIRT1 inhibitor on suppressing the growth of chemo-resistant human cancer cells. We showed that inhibition of SIRT1 effectively potentiated the cytotoxicity of 17-allylamino-17-demethoxygeldanamycin (17-AAG) and reversed Hsp90 inhibitor resistance in multidrug-resistant (MDR) human ovarian HeyA8-MDR cells. Amurensin G, a potent natural SIRT1 inhibitor, enhanced Hsp90 inhibitor-mediated abrogation of the Hsp90 chaperone function and accelerated degradation of mutated p53 (mut p53), an Hsp90 client protein, by up-regulation of ubiquitin ligase CHIP. Knock-down of CHIP significantly attenuated amurensin G-induced mut p53 degradation. Down-regulation of mut p53 reduced the expression of heat shock factor1 (HSF1)/heat shock proteins (Hsps), a major cause of Hsp90 inhibitor resistance, which led to sensitization of the MDR cells to the Hsp90 inhibitor by the SIRT1 inhibitor. Amurensin G potentiated cytotoxicity of the Hsp90 inhibitor in HeyA8-MDR cells through suppression of 17-AAG-induced Hsp70 and Hsp27 induction via down-regulation of mut p53/HSF1, and it caused activation of PARP and inhibition of Bcl-2. Our data suggests that SIRT1 inhibitors could be used to sensitize MDR cells to Hsp90 inhibitors, possibly through suppression of the mut p53/HSF1-dependent pathway, and a novel mut p53-directed action of SIRT1 inhibition could effectively prevent mut p53 accumulation in MDR cells.

• Bulletin of the Korean Chemical Society
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• v.21 no.10
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• pp.1041-1043
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• 2000

We present the effects of temperature (between 10 K and 298 K) and of hole concentration on the frequency and intensity of characteristic phonons in polycrystalline $La_2CuO_4-related$ compounds using FT-IR spectros-copy. The influences of the concentration of carrier doped on the phonon modes are prominent in the IR spectra of $La_2CuO_4-related$ compounds. For $La_2-xSrxCuO_4({\chi}=$ 0.00, 0.03, 0.07, 0.10, and 0.15) and electrochemically (or chemically) oxidized $La_2CuO_4$, the intensities of the transverse oxygen mode around 680cm $-^1$ which cor-responds mainly to Cu-O(1) stretching vibration in the basal plane of CuO6 octahedron, are decreased and dis-appeared depending on the Sr-substitution rate and the amount of excess oxygen, while the longitudinal oxygen mode around 510 cm $-^1$ corresponding to the Cu-O(2) stretching in the basal plane of CuO6 octahedron are near-ly invariable. In particular, after two cycles of cooling-heating between 10 K and 298 K for these sample, the phonons around 680 cm $-^1$ are blue shif 13-15 cm $-^1$, while the phonons around 510 cm $-^1$ are nearly constant. The introduction of the charge carrier by doping would give rise to the small contraction of CuO6 oc-tahedron as Cu $^3+$ requires a smaller site than Cu $^2+$, which results in the shortening of the Cu-O(1) bond length and Cu-O(2) bond length with the increased La-O(2) bond length. These results in the frequency shift of the characteristic phonons. The IR spectra of $La_2Li0.5Cu0.5O_4$ which exhibits an insulator behavior despite the $Cu^3+$ of nearly 100%, corroborate our IR interpretations. The mode around 710 cm $-^1$ corresponding to Cu-O(1) stretching vibration is still strongly remained even at low temperature (10 K). Thus, we conclude that the con-duction electrons formed within $CuO_2$ planes of $La_2CuO_4-related$ superconductors screen more effectively the transverse oxygen breathing mode around 680 $cm-^1$ depending on the concentration of the doped charge carrier in $La_2CuO_4-related$ compounds, which might use as a superconductivity probe.

• Journal of Fisheries and Marine Sciences Education
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• v.11 no.1
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• pp.69-87
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• 1999

This study had been analysed the establishment, the closing and the actual conditions of the fisheries school according to the four times revision and promulgation of the law of education of korea which were devided by the early term (the first Chosun educational decree), the middle term (the second Chosun educational decree) and the last term (the third and fourth Chosun educational decree), and also been investigated how the fisheries education of the school had been acted to the mobocracy and the assimilation policy and together with it's back ground through this analysis. The aim of this study is to contribute to the study of the history of the fisheries school education, analysis of change of the fisheries school education according to practical application of the Chosun educational decree. The summary of the characteristic of the each term are as under. First, in the early term of the fisheries education under the first Chosun educational decree, Experts were despatched to the each province with donated money from emperor and opened seasonal the fishing training centre, a kind of social fisheries education, and trained directly fishing technic and were going to train fisheries trainees regularly under name of elementary fisheries school. Japanese imperialism attached great importance to the vocational education in order to snack economical products from colonized Korea but actually had a purpose to train low quality technician who follow blindly their colony policy of Japanese imperialism. The fisheries schools in the circle of system in early time of Japanese imperialism, Kunsan public elementary fisheries school was established in April 1915, Yosu public elementary fisheries school was established ill May 1917 and Kyungnam Tongyoung training school was established in March 1917. Secondly, After 3.1 movement, the Japanese imperialism established an appeasement policy so called cultural politics and continued assimilation policy with skilful methods. After revision of the second Chosun educational decree, the Elementary vocational school was changed as the vocational training school. The school of fisheries education in middle of Japanese imperialism trained low quality technicians to snack fisheries resources from colonized Korea. After the middle of Japanese imperialism they paid attention on training fisheries technician through fisheries school rather than training school. With high interest and crowded volunteers, Kunsan public fisheries school was promoted in 1922, Tongyoung public fisheries school was promoted in 1923, Yongampo fisheries training school established in 1922 was promoted as Yongampo public fisheries school in 1926. Thirdly, in the time of the third and fourth Chosun educational decree, the end of Japanese imperialism, they met Pacific war after Japan vs China war. During the war time they considered the vocational school as the source of supply for materials and manpower and consequently had to expanded vocational education and systematically despatched students to war field and practiced military training. In 1938, Namhae public fisheries school was established and Chungjin fisheries school was permitted. But in order to supply manpower to Pacific war, the study period of Yosu public fisheries school was shorten from 5 years to 4 year in 1943 and also that of Tongyoung public fisheries school shorten in 1944.

• The Journal of Korean Philosophical History
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• no.56
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• pp.209-238
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• 2018

The purpose of this research is to analyze characteristics of the method of education or learning reflected in the teacher-student relationship in On Haeng Lok By Toe-gye and explore their relevance to modern education. By writing various works and conversing with his students, Toe-gye devoted himself in the education of the traditional Confucian principles. Specially, he taught his students based on two Confucian educative principles, namely Shim Deuk(心得) and Goong Haeng(躬行). Judging from this, Toe-gye can be seen as someone who tries to fulfill the role of teacher as dictated in the educative principles of the Confucianism. In Confucianism, teacher is responsible for forming a well-rounded view on life in student, rather than simply transmitting knowledge. As such, the teacher was supposed to find a harmonious way to create something new based on what was inherited from the past generation and try to do his best in learning new things himself and teaching his students. These Toe-gye managed to do successfully, earning his students' trust and respect. Being moved and inspired by their teacher, the students continued their intellectual pursuit. This relationship between Toe-gye and his students can be analyzed from the perspective of education method and discussed in terms of cognitive learning and adult learning. In terms of cognitive learning, the education method reflected in the relationship is similar to potential learning, insight learning, and imitation learning. In terms of adult learning, it is similar to self-directed learning and communicative learning.!