• Journal of The Korean Ophthalmological Society
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• v.58 no.8
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• pp.960-967
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• 2017

Purpose: To compare the macular choroidal thickness in patients with thyroid-associated ophthalmopathy (TAO) with those with normal tension glaucoma (NTG). Methods: A total of 70 normal eyes, 74 eyes with TAO and 60 eyes with NTG were enrolled in this study. All patients underwent spectral-domain optical coherence tomography (SD-OCT) (Cirrus HD-OCT, Carl Zeiss Meditec Inc., Dublin, CA, USA). Macular choroidal thickness was assessed using enhanced depth imaging. The average macular choroidal thickness was defined as the average value of three measurements: at the fovea and at the points located 1.5 mm in the nasal and temporal directions from the fovea. Generalized estimating equations were used to uncover factors affecting the average macular choroidal thickness. Results: The average, superior and inferior quadrant retinal nerve fiber layer thicknesses were significantly thinner in the NTG group compared with the TAO and control groups (p < 0.001). The average macular choroidal thickness of the TAO group, NTG group and controls was $281.01{\pm}60.06{\mu}m$, $241.66{\pm}55.00{\mu}m$ and $252.07{\pm}55.05{\mu}m$, respectively, which were significantly different (p = 0.013). The subfoveal, nasal and temporal side choroidal thicknesses were significantly thinner in the NTG group compared with the TAO group (p = 0.014, 0.012 and 0.034, respectively). Subjects with TAO were associated with a thicker average macular choroidal thickness compared with the NTG group after adjusting for age, sex, spherical equivalent and intraocular pressure (${\beta}=32.61$, p = 0.017). Conclusions: Macular choroidal thickness was significantly thicker in patients with TAO compared with those with NTG. Further evaluation is required to determine if a thick choroid in subjects with TAO has any role in glaucomatous optic neuropathy.

• Korean Journal of Remote Sensing
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• v.21 no.6
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• pp.445-456
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• 2005

The land surface parameters should be determined with sufficient accuracy, because these play an important role in climate change near the ground. As the surface reflectance presents strong anisotropy, off-nadir viewing results a strong dependency of observations on the Sun - target - sensor geometry. They contribute to the random noise which is produced by surface angular effects. The principal objective of the study is to provide a database of accurate surface reflectance eliminated the angular effects from MODIS 250m reflective channel data over Korea. The MODIS (Moderate Resolution Imaging Spectroradiometer) sensor has provided visible and near infrared channel reflectance at 250m resolution on a daily basis. The successive analytic processing steps were firstly performed on a per-pixel basis to remove cloudy pixels. And for the geometric distortion, the correction process were performed by the nearest neighbor resampling using 2nd-order polynomial obtained from the geolocation information of MODIS Data set. In order to correct the surface anisotropy effects, this paper attempted the semiempirical kernel-driven Bi- directional Reflectance Distribution Function(BRDF) model. The algorithm yields an inversion of the kernel-driven model to the angular components, such as viewing zenith angle, solar zenith angle, viewing azimuth angle, solar azimuth angle from reflectance observed by satellite. First we consider sets of the model observations comprised with a 31-day period to perform the BRDF model. In the next step, Nadir view reflectance normalization is carried out through the modification of the angular components, separated by BRDF model for each spectral band and each pixel. Modeled reflectance values show a good agreement with measured reflectance values and their RMSE(Root Mean Square Error) was totally about 0.01(maximum=0.03). Finally, we provide a normalized surface reflectance database consisted of 36 images for 2001 over Korea.

• The Korean Journal of Pharmacology
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• v.32 no.3
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• pp.323-334
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• 1996

Male Mongolian gerbils $(60{\sim}80g)$ were given DL-difluoromethylornithine (DFMO; 250mg/kg, ip) and methylglyoxal bis(guanylhydrazone) (MGBG; 50 mg/k, ip), respectively, 1 h prior to transient (7 min) occlusion of bilateral common carotid arteries (OBC7) and a daily dose of one of them for 6 days after recirculation, and the polyamine contents, activities of ornithine and S-adenosylmethionine decarboxylases (ODC and SAM-DC), and light microscopic findings of the hippocampus were evaluated. The hippocampal putrescine (PT) levels of the control gerbils treated with saline (STGr), markedly increased after OBC7, showing a peak level at 24 h after recirculation. The peak PT level was reduced in DFMO treated gerbils (DTCr) and in MGBG treated gerbils (MTGr). And 7 days after recirculation, the PT level of DTGr was decreased to about 75% of the PT level in the sham operated group (nonTGr) and to about 55% of the STGr level, respectively. The hippocampal spermidine (SD) level of STGr tended to decline, showing the lowest value at 8 h after recirculation. But the spermidine (SD) level of DTGr was somewhat higher at 8 h after OBC7 than those of STGr and MTGr The hippocampal spermine (SM) levels of all the experimental groups were little changed for 7 days after OBC. OBC7 markedly increased the hippocampal ODC activity. reaching a maximum (about 3 times higher than preischemic level) at 8 h and rapidly recovered to the control value by 24 h in STGr gerbils, and the OBC7-induced increase of ODC activity was significantly attenuated by DFMO or MGBG treatment. Whereas OBC7 induced a rapid decrease of the hippocampal SAMDC activity follwed by gradual recovery to the preischemic level, and the decrease of the SAMDC activity was slightly attenuated by DFMO or MGBG treatment. 7 Days after OBC7 the histological finding of the hippocampal complex stained with cresyl violet showed an extensive delayed neuronal damage in the CA1 region and to a lesser extent, in the dentate gyrus, sparing the CA3 region. And the neuronal death was aggevated by DFMO but significantly attenuated by MGBG. The immunochemical reactivity of hippocampus to anti-GFAP antibody was significantly increased in the CA1 region and to a lesser extent, in the dentate gyrus 7 days after OBC7, but was little changed in the CA3. And the increase of the anti-GFAP immunoreactivity was moderately enhanced by DFMO and significantly suppressed by MGBG. These results suggest that the polyamine metabolism may play a modulatory role in the ischemic brain damage.

• Microbiology and Biotechnology Letters
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• v.37 no.2
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• pp.160-169
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• 2009

Poly-$\gamma$-glutamic acid ($\gamma$-PGA) was mixed natural flora of Bacillus subtilis, contaminated from cooked soybeans. Also, it was performed to find out the antiallergic activity by using NC/Nga mice, in vitro. The $\gamma$-PGA (PGA-HM : PGA-high molecular weight), Molecular weight 300 kDa, was decomposed and made PGA-LM (PGA-low molecular weight) which has molecular weight below 30 kDa by sonication. Therefore, it was same result between PGA-HM and PGA-LM, and reported PGA-LM as basic result. We found that PGA-LM contains antiallergic efficacy that inhibit B cells and Th2 cells activation from isolated CD4+T cells in NC/Nga atopic dermatitis model mice, and not show a cytotoxicity in the hFCs. To investigate the effects of these PGA-LM in vitro, isolation of splenic B cell and CD4+ T cells in atopic dermatitis mice were used. To elucidate the role of PGA-LM in anti-CD40+ interleukin-4 (IL-4)-mediated B-cell activation, showed that the capacity of B cells to expression IL-$1\beta$, IL-6, and TNF-$\alpha$ mRNA down-regulated, and IL-10 mRNA up-regulation by PGA-LM treatment, but it had no effect on TGF-$\beta$ expression. In addition to CD4+IFN-$\gamma$+ and CD4+CD25+foxp3+, the functions of PGA-LM in the development of the CD4+CD25+foxp3+ and CD4+IFN-$\gamma$+cells, the phenotype and functions of PGA-LM induced CD4+CD25+foxp3+, and CD4+IFN-$\gamma$+cells in CD4+T cells. These results suggested that PGA-LM could change cytokine production and generate CD4+CD25+foxp3+ Tregs in NC/Nga mice, and may be effective for immunotherapy in patients with AD.

• The Korean Journal of Pharmacology
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• v.31 no.1 s.57
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• pp.39-51
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• 1995

The roles of ${\beta}-adrenoceptor$ were well known in hyperthyroidal heart, but not with ${\alpha}-adrenoceptor$. So we studied the effects of phenylephrine on membrane potential, intracellular sodium activity ($a^{i}_{Na}$), twitch force, and intracellular pH ($pH_i$) by continuous intracellular recordings with ion-selective and conventional microelectrodes in the papillary muscles of hyperthyroid guinea pig heart. ${\alpha}_1-adrenoceptor$ stimulation by phenylephrine (10^{-5}\;or\;3{\times}10^{-5}M$) produced the following changes: variable changes in action potential duration, a hyperpolarization ($1.5{\pm}0.1mM$) of the diastolic membrane potential, an increase in $a^{i}_{Na}\;(0.4{\pm}0.15mM)$, a stronger positive inotropic effect ($220{\pm}15%$), an increase in $pH_i\;(0.06{\pm}0.002\;unit)$. These changes were flocked by prazosin and atenolol. This indicated that the changes in membrane potential, $a^{i}_{Na}$ twitch force, and $pH_i$ are mediated by a stimulation of the ${\alpha}_1-adrenoceptor$. Ethylisopropylamiloride ($10^{-5}$) also blocked the increase in $a^{i}_{Na}$ and twitch force. On the other hand, strophanthidin, tetrodotoxin, $Cs^+$ or verapamil did not block the increase in $a^{i}_{Na}$ and twitch force. Thus, it was suggested that ${\alpha}_1-adrenoceptor$ stimulation increased $a^{i}_{Na}\;and\;pH_i$ by stimulation of $Na^{+}-H^{+}$ exchange, thereby allowing intracellular alkalinization and $a^{i}_{Na}$ increase. These results were very different from euthyroidal heart which showed ${\alpha}_1-adrenoceptor$-induced decrease in $a^{i}_{Na}$ and initial negative inotropic effect. From the above results, it was concluded that ${\alpha}_1-adrenoceptor$ had a important role in hyperthy-roidal heart.

• Pediatric Infection and Vaccine
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• v.25 no.2
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• pp.61-71
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• 2018

Purpose: Research on the clinical role of Staphylococcus aureus as a pathogen in acute gastroenteritis (AGE) in children has been scarce. This study aimed to clarify the prevalence and clinical correlation of S. aureus detection in children with AGE. Methods: Fecal samples were collected from children with symptoms of AGE who visited a secondary hospital between January 2012 and December 2015. The samples were sent to the Seoul Metropolitan Government Research Institute of Public Health and Environment to test for pathogenic organisms. Clinical patterns were analyzed through medical record review. Results: Among the 663 participants, the bacteria detection rate was 26.2% (n=174), the virus detection rate was 29.7% (n=197), and the non-detection rate was 43.1% (n=286). S. aureus was tested positive from 102 cases and was confirmed as a single pathogen in 53 cases. It was the third most common pathogen. The prevalence by age was highest (45.3%) in 0-2 year-olds. Most cases occurred in summer. Symptoms included diarrhea (71.7%), vomiting (67.9%), fever (49.1%), and abdominal pain (37.7%). Only vomiting showed a significant difference between the S. aureus group and the non-detection group (67.9% vs. 43.0%; P=0.001). Among enterotoxins, the higher incidence of vomiting was associated with classical staphylococcal enterotoxins (SEA, SEB, SEC, SED, and SEE) and SEH (P=0.027). Conclusions: S. aureus was the bacteria commonly isolated from children with AGE. Our study identified cases of staphylococcal AGE in children based on fecal samples and confirmed the characteristic symptoms, affected age groups, seasonal distribution, and correlation with enterotoxins.

• Communications of Mathematical Education
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• v.23 no.4
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• pp.977-998
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• 2009

In this article, we give a comparative study on the last 300 years of USA and Korean tertiary mathematics. The first mathematics classes in United States were offered before July, 1638, but the real founding of tertiary mathematics courses was in 1640 when Henry Dunster assumed the duties of the presidency at Harvard. President Dunster read arithmetics and geometry on Mondays and Tuesdays to the third year students during the first three quarters, and astronomy in the last quarter. So tertiary mathematics education in United States began at Harvard which is the oldest college in USA. After 230 years since then, Benjamin Peirce in 1870 made a major and first American contribution to mathematics and got an attention from European mathematicians. Major change on the role of Harvard mathematics from teaching to research made by G.D. Birkhoff when he joined as an assistant professor in 1912. Tertiary mathematics education in Korea started long before Chosun Dynasty. But it was given to only small number of government actuarial officers. Modern mathematics education of tertiary level in Korea was given at Sungkyunkwan, Ewha, Paichai, and Soongsil. But all college level education opportunity, particularly in mathematics, was taken over by colonial government after 1920. And some technical and normal schools offered some tertiary mathematics courses. There was no college mathematics department in Korea until 1945. After the World War II, the first college mathematics department was established, and Rimhak Ree in 1949 made a major and first Korean contribution to modern mathematics, and later found Ree group. He got an attention from western mathematicians for the first time as a Korean. It can be compared with Benjamin Peirce's contribution for USA.

• Journal of the Korean earth science society
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• v.41 no.6
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• pp.588-598
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• 2020

The seafloor geology of Ieodo, a submerged volcanic island, has been poorly understood, although this place has gained considerable attention for ocean and climate studies. The main purpose of the study is to understand and elucidate types, distribution patterns and provenance of the surficial sediments in and around the Ieodo area. For this purpose, 25 seafloor sediments were collected using a box-corer, these having been analyzed for grain sizes. XRD (X-ray Diffraction) analysis of fine-grained sediments was conducted for characterizing clay minerals. The peak of Ieodo exists in the northern region, while in the southern area, shore platforms occur. The extensive platform in the south results from severe erosion by strong waves. However, the northern peak still survived from differential weathering. Grain size analyses indicated that gravels and gravelly sands with skeletons and shells were distributed predominantly on the volcanic apron and shore platform. Muddy sediments were found along the Ieodo and the adjacent deeper seafloor. Based on the analysis of clay mineral composition, illites were the most abundant in fine muds, followed by chlorites and kaolinites. The ratio plots of clay minerals for the provenance discrimination suggested that the Ieodo muds were likely to be derived from the Yangtze River (Changjiang River). As a consequence, gravels and gravelly sands with bioclastics may be supplied from the Ieodo volcanic apron by erosion processes. Wave activities might play a major role in transportation and sedimentation. In contrast, fine muds were assumed to be derived from the inflow of the Yangtze River, particularly in summer. Deposition in the Ieodo area is, therefore, probably controlled by the inflow from the Changjiang Dilute Water and summer typhoons from the south.

• Journal of Service Research and Studies
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• v.13 no.2
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• pp.181-203
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• 2023

YouTube exhibits a hybrid personality, incorporating traits of both over-the-top (OTT) and personal broadcasting platforms. However, limited research has investigated these hybrid characteristics, particularly in the context of paid YouTube channel memberships. Therefore, building upon consumption value theory and prior literature, this study examines the influence of consumption value factors associated with paid YouTube channel memberships on usage satisfaction and continuance intention. Specifically, the study identifies four perceived consumption value factors (functional, social, emotional, and epistemic values) within the paid YouTube channel membership context and assesses their impact on usage satisfaction and continuance intention. Additionally, the study explores the moderating role of conditional value (the experience of watching live streams on paid YouTube channels) in these relationships. Data was collected via an online survey from Korean adults who subscribed to multiple paid YouTube channel memberships, resulting in 274 responses. The proposed hypotheses were tested using structural equation modeling (SEM). The SEM results indicate that all four consumption value factors significantly influence usage satisfaction, with usage satisfaction in turn positively affecting continuance intention. Furthermore, the study reveals that conditional value moderates the relationships between functional/emotional values and usage satisfaction, as well as between usage satisfaction and continuance intention. This study is the first to focus on YouTube channel paid memberships, which encompass characteristics from both OTT and personal broadcasting platforms. It is anticipated that this research will offer insights to personal broadcasters and stakeholders regarding the motivational factors that impact user satisfaction and encourage subscriptions to channel memberships.

• Radiation Oncology Journal
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• v.17 no.3
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• pp.209-216
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• 1999

Purpose : To evaluate the effectiveness of external radiation therapy and the prognostic factors, we retrospectively analyzed therapeutic results of malignant extrahepatic biliary obstruction (EHBO). Methods and Materials : We analyzed the results of the external radiation therapy in 59 patients of inoperable malignant EHBO who had been treated with more than 10 Gy of external radiation therapy from April 1984 to December 1990. There were 21 stomach cancer ($35.6\%$), 12 pancreas cancer ($20.3\%$), 15 extrahepatic biliary cancer ($18.0\%$) and 11 another cancer ($18.0\%$). Their pathologies were confirmed in 31 patients ($52.5\%$). They divided into 27 adenocarcinoma and 4 nonadenocarcinoma. Their chief complaints were jaundice in 47 patients ($79.7\%$) and abdominal pain in 15 patients ($49.2\%$). Twelve patients had slightly increased bilirubin level in liver function test without jaundice. We treated twenty four patients ($40.6\%$) with percutaneous transhepatic biliary drainage (PTBD) and 32 patients ($54\%$) with systemic chemotherapy (CT). We performed external radiation therapy (ERT) upto $10.8\~55.8$ Gy (median 37.8 Gy) with palliative aim. Results : Overall median survival duration was $7.80\pm1.15$ months. The response rates of jaundice were $81.8\%$ in PTBO group and $66.7\%$ in non-PTBD group without statistical significance. The improving rate of jaundice was not significantly different in decreased ratio of total bilirubin level. But abdominal pain was more decreased in CT group than non-CT group (p<0.05). The significant prognostic factors were high performance status (Karnofski Performance Status >70), total radiation dose more than 35 Gy and good response of pain after therapy. There were increased in bacterial cholagitis in PTBD group and gastrointestinal complications in CT group. Conclusion : External radiotheapy could improve jaundice and abdominal pain in malignant EHBO patients, Overall survival duration was prolonged in patients with higher performance status and patients who had been treated with more than 35 Gy of total radiation dose. In the future, we expect not only better palliative role but also the prolongation of survival of using the ERT combined with other treatment method. But to achieve certain conclusion, we need luther study consisted with many kinds of treatment methods including new technologies in RT.