• Title/Summary/Keyword: A/D mechanism

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Media Scholars and Power: The politicized intellectuals hanging on the dangerous rope (언론학자와 권력: 정치화된 지성의 위험한 줄타기)

  • Choi, Nakjin;Kim, Sunghae
    • Korean Journal of Legislative Studies
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    • v.22 no.2
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    • pp.113-156
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    • 2016
  • Media scholars take a lion stake in power circle. Not only do they take a part in media policies but seize prestigious positions like board members in Korea Communication Commission(KCC). Unfortunately, though, little has been known about who they are, what qualifications they have, and whether they meet public interests. This paper attempts to unveil the mechanism of those politicized intellectuals who are specialized on the media. Two categories divided into 'representative' and 'expertise' are employed for this purpose. On the one hand, the representative means the degree of committment into such public services as participation in conferences or non-profit organizations. On the other hand, the number of research articles, books and projects belong to the expertise. Evaluation levels consist of 'excellence, good and average' were allocated to those scholars who are(were) in 'Power Hole,' where decision makings come into being. Some interesting observations were made though this study. First of all, such criteria as representative and expertise vaguely suggested by the laws were hardly fit into those intellectuals, Rarely did they commit into public service let alone showing vigilance in academic activities. Secondly, both ideological loyalty and political activities in line with the government had much to do with taking such positions. Thirdly, not surprisingly, it showed that to graduate from Seoul National University and have Ph.D. degree from U.S.A. was one of the most essential factors. In final, most of them were very good at taking advantage of the press in way of boosting their publicity. To attend at policy making processes either in form of board members or advisers is inevitable for media experts. However, as shown in this study, such qualification of public service and academic eagerness shouldn't be underestimated. Academic integrity not selling intelligence solely for private interests needs to be protected as well. The authors hope this study to provide a valuable opportunity to establish a kind of ethical standards in participating into politics.

Discovery of UBE2I as a Novel Binding Protein of a Premature Ovarian Failure-Related Protein, FOXL2 (조기 난소 부전증 유발 관련 단백질인 FOXL2의 새로운 결합 단백질 UBE2I의 발견)

  • Park, Mira;Jung, Hyun Sook;Kim, Hyun-Lee;Pisarska, Margareta D.;Ha, Hye-Jeong;Lee, Kangseok;Bae, Jeehyeon;Ko, Jeong-Jae
    • Development and Reproduction
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    • v.12 no.3
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    • pp.289-296
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    • 2008
  • BPES (Blepharophimosis/Ptosis/Epicanthus inversus Syndrome) is an autosomal dominant disorder caused by mutations in FOXL2. Affected individuals have premature ovarian failure (POF) in addition to small palpebral fissures, drooping eyelids, and broad nasal bridge. FOXL2 is a member of the forkhead family transcription factors. In FOXL2-deficient ovaries, granulosa cell differentiation dose not progress, leading to arrest of folliculogenesis and oocytes atresia. Using yeast two-hybrid screening of rat ovarian cDNA library with FOXL2 as bait, we found that small ubiquitin-related modifier (SUMO)-conjugating E2 enzyme UBE2I protein interacted with FOXL2 protein. UBE2I also known as UBC9 is an essential protein for processing SUMO modification. Sumoylation is a form of post-translational modification involved in diverse signaling pathways including the regulation of transcriptional activities of many transcriptional factors. In the present study, we confirmed the protein-protein interaction between FOXL2 and UBE2I in human cells, 293T, by in vivo immunoprecipitation. In addition, we generated truncated FOXL2 mutants and identified the region of FOXL2 required for its association with UBE2I using yeast-two hybrid system. Therefore, the identification of UBE2I as an interacting protein of FOXL2 further suggests a presence of novel regulatory mechanism of FOXL2 by sumoylation.

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Neuroprotective effects of geneticin (G418) via apoptosis in perinatal hypoxic-ischemic brain injury (주산기 저산소성 허혈성 뇌손상에서 항고사를 통한 geneticin (G418)의 신경보호 효과)

  • Ju, Mi;Lee, Hyun Ju;Lee, Sun Ju;Seo, Eo Su;Park, Hye Jin;Lee, Kye Yang;Lee, Gyeong Hoon;Choi, Eun Jin;Kim, Jin Kyung;Lee, Jong Won;Chung, Hai Lee;Kim, Woo Taek
    • Clinical and Experimental Pediatrics
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    • v.51 no.2
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    • pp.170-180
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    • 2008
  • Purpose : Some antibiotics were known to exert neuroprotective effects in the animal model of hypoxic-ischemic (H-I) brain injury, but the mechanism is still unclear. A recent study reported that geneticin (G418), an aminoglycoside antibiotic, increased survival of human breast cancer cells by suppressing apoptosis. We investigated the neuroprotective effects of systemically administrated geneticin via anti-apoptosis following the H-I brain injury Methods : Seven-day-old Sprague-Dawley rat pups were subjected to unilateral (left) common carotid artery occlusion followed by 2.5 hours of hypoxic exposure and the cortical cell culture of rat brain was done under a hypoxic incubator. Apoptosis was measured in the injured hemispheres 7 days after H-I insult and in the injured cells from hypoxic chamber using morphologic analysis by Terminal dUTP Nick-end Labeling(TUNEL) assay and immunohistochemistry for caspase-3, and cytologic analysis by western blot and real time PCR for bax, bcl-2, and caspase-3. Results : The gross appearance and hematoxylin and eosin stain revealed increased brain volume in the geneticin-treated animal model of perinatal H-I brain injury. The TUNEL assay revealed decreased apoptotic cells after administration of geneticin in the cell culture model of anoxia. Immunohistochemistry showed decreased caspase-3 expression in geneticin-treated cortical cell culture. Western blot and real-time PCR showed decreased caspase-3 expression and decreased ratio of Bax/Bcl-2 expression in geneticin-treated animal model. Conclusion : Geneticin appears to exert a neuroprotective effect against perinatal H-I brain injury at least via anti-apoptosis. However, more experiments are needed in order to demonstrate the usefulness of geneticin as a preventive and rescue treatment for H-I brain injuries of neonatal brain.

The Efficacy Evaluation of Tourmaline-Ionized Water in Animal Study (투어마린이온활성수의 효능 평가)

  • Yoon, Yang-Suk;Kim, Dong-Heui;Qi, Xu-Feng;Song, Soon-Bong;Jung, Jong-Ho;Joo, Kyung-Bok;Teng, Yung-Chien;Lee, Kyu-Jae
    • Applied Microscopy
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    • v.39 no.4
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    • pp.311-317
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    • 2009
  • This study was performed using animals to confirm the effect of tourmaline-ionized water (TIW) the properties of which were changed by tourmaline energy and electric discharge. In the ICR mice fed high-fat diet, body weight increasing rate of the TIW-treated group (Exp) was generally decreased and moreover exhibited significance at 11th week (P<0.05) compared with the control (Con) group fed distilled water, although water intake of the Exp group was lower than that of the Con group. In the ICR mice with $CCl_4$-induced hepatotoxicity, AST and ALT activities of the Exp group were not significant but showed some decreasing trend, and histological damage of liver was less compared with thatof the Con group. On the study of ethanol-induced hangovers in Sprague-Dawley rat, blood alcohol concentration was significantly decreased (P<0.01), activity of GST, antioxidant enzyme related to the alcohol metabolism, was increased in liver tissue (P<0.05), and AST and ALT show a tendency to be decreasedin the Exp group. These results suggest that drinking TIWhas not only some obesity preventing effect but also an alcohol detoxification effect and liver protecting effect in vivo. It is supposed due to a structural change of water cluster and a property which maintains the changed structure through tourmaline energy and electric discharge. Therefore, TIW has a potentiality to be developed as functional water with several beneficial effects as well as for daily drinking, but further study on the mechanism related with efficacy will be necessary.

Implication of High Mobility Group Box 1 (HMGB1) in Multicellular Tumor Spheroid (MTS) Culture-induced Epithelial-mesenchymal Transition (Multicellular tumor spheroid (MTS) 배양에 의한 EMT에서 HMGB1의 역할)

  • Lee, Su Yeon;Ju, Min Kyung;Jeon, Hyun Min;Kim, Cho Hee;Park, Hye Gyeong;Kang, Ho Sung
    • Journal of Life Science
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    • v.29 no.1
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    • pp.9-17
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    • 2019
  • As tumors develop, they encounter microenvironmental stress, such as hypoxia and glucose depletion, due to poor vascular function, thereby leading to necrosis, which is observed in solid tumors. Necrotic cells are known to release cellular cytoplasmic contents, such as high mobility group box 1 (HMGB1), into the extracellular space. The release of HMGB1, a proinflammatory and tumor-promoting cytokine, plays an important role in promoting inflammation and metabolism during tumor development. Recently, HMGB1 was shown to induce the epithelial-mesenchymal transition (EMT) and metastasis. However, the underlying mechanism of the HMGB1-induced EMT, invasion, and metastasis is unclear. In this study, we showed that noninvasive breast cancer cells MCF-7 formed tightly packed, rounded spheroids and that the cells in the inner regions of a multicellular tumor spheroid (MTS), an in vitro model of a solid tumor, led to necrosis due to an insufficient supply of O2 and glucose. In addition, after 7 d of MTS culture, the EMT was induced via the transcription factor Snail. We also showed that HMGB1 receptors, including RAGE, TLR2, and TLR4, were induced by MTS culture. RAGE, TLR2, and TLR4 shRNA inhibited MTS growth, supporting the idea that RAGE/TLR2/TLR4 play critical roles in MTS growth. They also prevented MTS culture-induced Snail expression, pointing to RAGE/TLR2/TLR4-dependent Snail expression. RAGE, TLR2, and TLR4 shRNA suppressed the MTS-induced EMT. In human cancer tissues, high levels of RAGE, TLR2, and TLR4 were detected. These findings demonstrated that the HMGB-RAGE/TLR2/TLR4-Snail axis played a crucial role in the growth of the MTS and MTS culture-induced EMT.

Phosphorus and Nitrogen Reduction from Animal Wastewater with MAP Process (축산폐수에서 질소$\cdot$인의 추출을 위한 MAP공정 개발)

  • Oh I. H.;Lee J. H.;Jeung D. S.;Jo J. W.
    • Journal of Animal Environmental Science
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    • v.11 no.3
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    • pp.207-214
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    • 2005
  • To reduce phosphorus and nitrogen from the swine wastewater, magnesium chloride $(MgCl_2)$ was used as a reaction material for both soluble phosphorus (SP) and ammonia-nitrogen (AN). The initial value of SP content were $471mg/\ell$ far aeration test and $515 mg/\ell$ for NaOH addition test, but treatment of $MgCl_2$ reduced SP value to $5mg/\ell$ and $4mg/\ell$. The removal efficiency of $MgCl_2$ for SP showed $99\%$ in both treatment, and the removal efficiency of $MgCl_2$ for AN showed $15\%$ with treatment of aeration and $18\%$ with NaOH. All the experiments were done in a low temperature of 6 to $8^{\circ}C$, suggesting that this methods are possibly able to apply to a cold weather conditions. Moreover, the struvite crystal structure was identified by electronic microscope, implying that $MgCl_2$ is an effective material for removal of SP from swine wastewater In addition to the increased removal rate of the AN in wastewater, both $MgCl_2$ and $KH_2PO_4$ were added. The SP value was reduced by $99\%$ with 2g addition of the phosphate. The SP removal rate by 4g addition of the phosphate was increased only as $15-19\%$, but the quantity of removed SP was higher than that of 2g addition test. The value of AN was not reduced as expected by adding $KH_2PO_4$. The AN removal rate were low as $18\%$ and $15\%$ like as the level of the former test with $MgCl_2$ alone. Therefore, it is needed to examine closely the reaction mechanism f3r reducing both SP and AN simultaneously.

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Estimating Carrying Capacity of Lake Shihwa for Water Quality Management (수질관리를 위한 시화호의 환경용량 산정)

  • Kim, Hyung-Chul;Choi, Woo-Jeung;Lee, Won-Chan;Koo, Jun-Ho;Lee, Pil-Yong;Park, Sung-Eun;Hong, Seok-Jin;Jang, Ju-Hyoung
    • Journal of Environmental Science International
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    • v.16 no.5
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    • pp.571-581
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    • 2007
  • The mechanism of water pollution in Lake Shihwa, one of highly eutrophicated artificial lakes in Korea, has been studied using a numerical 3D physical-biochemical coupled model. In this study, the model was applied to estimate the contribution of land-based pollutant load to water quality of heavily polluted Lake Shihwa. The chemical oxygen demand(COD) was adopted as an index of the lake water quality, and the spatial distribution of an average COD concentration during the summer from 1999 to 2000 was simulated by the model. The simulated COD showed a good agreement with the observed data. According to reproducibility of COD, the high-est levels between 8 and 9 mg/L were shown at the inner site of the lake with inflow of many rivers and ditches, while the lowest was found to be about 5 mg/L at the southwestern site near to dike gate. In the pre-diction of water quality of Lake Shihwa, COD showed still higher levels than 3 mg/L in case of reduction of 95% for land-based pollutant load. This suggests that the curtailment of land-based pollutant load is not only sufficient but the improvement of sediment quality or the increase of seawater exchange should be considered together to improve a water quality in Lake Shihwa.

Clinical Effect of Low-dose Long-term Erythromycin on Diffuse Panbronchiolitis (미만성 범세기관지염에서 Erythromycin 소량장기투여 효과)

  • Kim, Young-Whan;Park, Gye-Young;Yoo, Chul-Gyu;Han, Sung-Koo;Shim, Young-Soo;Kim, Keun-Youl;Han, Yong-Chol
    • Tuberculosis and Respiratory Diseases
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    • v.41 no.2
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    • pp.127-134
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    • 1994
  • Background : Diffuse panbronchiolitis(DPB) is a chronic inflammatory lung disease of unknown etiology which has characteristic clinical, radiological and pathological features, and is distinguished from bronchial asthma, chronic bronchitis, pulmonary emphysema, bronchiectasis, or alveolitis. Clinically, patients with DPB have chronic cough, purulent sputum, exertional dyspnea, and finally respiratory failure. Until a few years ago, the prognosis of DPB had been thought to be very grave, because there had been no effective treatment for the disease. But recent1y, low-dose long-term erythromycin was found to be very effective on DPB. Even though DPB is prevalent in Japan, and is known to be rare outside of Japan, we have a1ready reported the clinical features of 16 DPB cases in Korea. We tried low-dose long-term erythromycin on DPB patients and analyzed the clinical effect of erythromycin. Methods : We analyzed the changes of subjective symptoms, physical signs, pulmonary function tests and chest X-rays on 14 DPB patients with more than 6 months erythromycin treatment during the period from September 1989 to August 1992 in Seoul National University Hospital. Results : 1) Subjective symptoms improved in all patients within 2-3 months, and 54.5% of the patients showed no symptom after one year of treatment. 2) Crackles and wheezing decreased in 92.9% of the patients after 3 months and completely disapppeared in 63.5% of the patients after one year of treatment. 3) FVC and FEV1 increased remarkably during the first 3 months, and slowly increased thereafter, reaching normal level after one year of treatment. 4) Small nodular lesions on chest X-ray decreased in all patients, and chest PA was normal in 36.4% of the patients after one year of treatment. 5) There was side effect in one patient, stopping medication because of dyspepsia. One patient stopped medication because of no symptom after 16 months of treatment, but her symptom recurring after one month, improving again after retreatment. Conclusion: Low-dose long-term erythromycin showed ramarkable effectiveness on DPB. Further studies are needed on the mechanism of the drug and the duration of the treatment.

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The Effect of Au Addition on the Hardening Mechanism in Ag-30wt%Pd-10wt%Cu Alloy (Ag-30wt% Pd-10wt% Cu 3원합금(元合金) 및 Au 첨가합금(添加合金)의 시효경화특성(時效硬化特性))

  • Lee, K.D.;Nam, S.Y.
    • Journal of Technologic Dentistry
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    • v.21 no.1
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    • pp.27-41
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    • 1999
  • The Ag-Pd-Cu alloys containing a small amount of Au is commonly used for dental purposes, because this alloy cheaper than Au-base alloys for clinical use. However, the most important characteristic of this alloy is age-hardenability, which is not exhibited by other Ag-base dental alloys. The specimens used were Ag-30Pd-10Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electric furnace and centrifugal casting machine in Ar atmosphere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at 350-$550^{\circ}C$ Age-hardening characteristic of the small Au-containing Ag-Pd-Cu dental alloys were investigated by means of hardness testing, X-ray diffraction and electron microscope observations, electrical resistance, differential scanning calorimetric, energy dispersed spectra and electron probe microanalysis. Principal results are as follows ; Maximum hardening occured in two co-phases of ${\alpha}_2$ + PdCu In stage II, decomposition of the $\alpha$ solid solution to a PdCu ordered phase($L1_o$ type) and an Ag-rich ${\alpha}_2$ phase occurred and a discontinuous precipitation occurred at the grain boundary. From the electron microscope study, it was concluded that the cause of age-hardening in this alloy is the precipitation of the PdCu redered phase, which has AuCu I type face-centered tetragonal structure. Precipitation procedure was ${\alpha}{\to}{\alpha}_1+PdCu{\to}{\alpha}_2+PdCu$ at Pd/Cu = 3 Pd element of Ag-Pd-Cu alloy is more effective dental alloy on anti-corrosion and is suitable to isothermal ageing at $450^{\circ}C$.

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The Effect of Au Addition on the Hardening Mechanism in Ag-20wt% Pd-20wt% Cu (Ag-20wt% Pd-20wt% Cu 3원합금(元合金) 및 Au첨가합금(添加合金)의 시효경화특성(時效硬化特性))

  • Park, M.H.;Bae, B.J.;Lee, H.S.;Lee, K.D.
    • Journal of Technologic Dentistry
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    • v.19 no.1
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    • pp.21-35
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    • 1997
  • The Ag-Pd-Cu alloys containing a small amount of Au is commonly used for dental purposes, because this alloy is cheaper than Au-base alloys for clinical use. However, the most important characteristic of this alloy is age-hardenability, which is not exhibited by other Ag-base dental alloys. The specimens used were Ag-20Pd-20Cu ternary alloy and Au addition alloy. These alloys were melted and casted by induction electic furace and centrifugal casting machine in Ar atmoshpere. These specimens were solution treated for 2hr at $800^{\circ}C$ and were then quenched into iced water, and aged at $350{\sim}550^{\circ}C$ Age-hardening characteristics of the small Au-containing Ag-pPd-Cu dental alloys were investigated by means of hardness testing, X-ray diffraction and electron microscope observations, electrical resistance, differential scanning calorimetric, emergy dispersed spectra and electron probe microanalysis. Principal results are as follows : Hardening occured in two stages, I. e., stage I in low temperature and stage II in high temperature regions, during continuous aging. The case of hardening in stage I was due to the formation of the Llo type face centered tetragonal PdCu-ordered phase in the grain interior and hardening in stage I was affedted by the Cu concentration. In stage II, decomposition of the $\alpha$ solid solution to a PdCu ordered phase(L1o type) and an Agrich ${\alpha}2$ phase occurred and a discontiunous precipitation occurred at the grain boundary. Form the electron microscope study, it was concluded that the cause of age-hardening in this alloy is the precipitation of the PdCu ordered phase, which has AuCu I type face-centered tetragonal structure. Precipitation procedure was ${\alpha}\to{\alpha}+{\alpha}2+PdCu\to{\alpha}1+{\alpha}2+PdCu$ at Pd/Cu = 1 Ag-Pd-Cu alloy is more effective dental alloy as ageing treatment and is suitable to isothermal ageing at $450^{\circ}C$.

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