• Journal of the Korean Magnetics Society
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• v.17 no.2
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• pp.81-85
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• 2007

MnTe layers of high crystalline quality were successfully grown on Si(100) : B and Si(111) substrates by molecular beam epitaxy (MBE). Under tellurium-rich condition and the substrate temperature around $400^{\circ}C$, a layer thickness of $700{\AA}$ could be easily obtained with the growth rate of $1.1 {\AA}/s$. We investigated the structural, magnetic and transport properties of MnTe layers by using x-ray diffraction (XRD), superconducting quantum interference device (SQUID) magnetometry, and physical properties measurement system (PPMS). Characterization of MnTe layers on Si(100) : B and Si(111) substrates by XRD revealed a hexagonal structure of polycrystals with lattice parameters, ${\alpha}=4.143{\pm}0.001{\AA}\;and\;c=6.707{\pm}0.001{\AA}$. Investigation of magnetic and transport properties of MnTe films showed anomalies unlike antiferromagnetic powder MnTe. The temperature dependence of the magnetization data taken in zero-field-tooling (ZFC) and field-cooling (FC) conditions indicates three magnetic transitions at around 21, 49, and 210 K as well as the great irreversibility between ZFC and FC magnetization in the films. These anomalies are attributable to a magnetic-elastic coupling in the films. Magnetization measurements indicate ferromagnetic behaviour with hysteresis loops at 5 and 300 K for MnTe polycrystalline film. The coercivity ($H_c$) values at 5 and 300 K are 55 and 44 Oe, respectively. In electro-transport measurements, the temperature dependence of resistivity revealed a noticeable semiconducting behaviours and showed conduction via Mott variable range hopping at low temperatures.

• Tuberculosis and Respiratory Diseases
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• v.39 no.1
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• pp.42-54
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• 1992

Background:It has been suggested that the cyclooxygenase metabolites play an important role in changes of early hemodynamic parameters in the endotoxin-induced acute lung injury. But there have been many debates about their role in the late increase of alveolar-capillary permeability, and it is not known whether they act directly or indirectly through oxygen free radicals which have been known to be produced during the metabolic process of cyclooxygenase pathway. So we performed this study to identify the pathogenetic role of cyclooxygenase metabolites in the endotoxin-induced acute lung injury in domestic pigs. Method: We infused endotoxin into 8 domestic pigs; endotoxin only (n=3), and pretreatment with indomethacin (n=5). We observed the sequential changes in hemodynamic parameters, the concentration of plasma oxidized glutathione (GSSG) in pulmonary arterial and venous blood, and albumin content in bronchoalveolar lavage fluid (BALF). Results: 1) While cardiac output decreased, mean pulmonary arterial pressure, pulmonary vascular resistance, and alveolar-arterial oxygen difference increased over phase 1 (0-2hr) and phase 2 (2-4.5hr) by endotoxin, indomethacin attenuated the decrease in cardiac output during phase 1 and increase in mean pulmonary arterial pressure, pulmonary vascular resistance, and alveolar-arterial oxygen difference during both phases. 2) The increase in plasma GSSG content during phase 2 was not attenuated by indomethacin. 3) The content of BALF albumin was significantly lower in indomethacin groups than that of endotoxin group. Conclusion: These results suggest that it is likely that cyclooxygenase metabolites have an effect on endotoxin-induced acute lung injury during both phases probably through direct action.

• The Journal of Korean Academy of Prosthodontics
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• v.47 no.1
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• pp.82-90
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• 2009

Statement of problem: Recently, as patients' expectation and interest for esthetics are increasing, concerns of esthetic restoration for removable dentures as well as fixed prosthodontics are also increasing. And the color stability of artificial teeth will affect a long term success rate of the denture. But the stain or discoloration of these artificial teeth as well as denture resin has caused esthetic problem. Purpose: This study was designed to evaluate the influence on color stability of artificial teeth when soy sauce, red pepper paste and coffee which many Koreans have eaten were applied. Material and methods: For artificial teeth type(Endura $Anterio^{(R)}$, Physio $Duracross^{(R)}$, Trubyte $Biotone^{(R)}$) selected for the study, 10 specimens each were soaked into individual beakers of soy sauce, red pepper paste, coffee and distilled water. And $L^*$, $a^*$, $b^*$ value were measured for evaluation of the color difference (${\Delta}E^*$) with spectrophotometer on the 1 day, 1 week, 2 weeks, 4 weeks and 8 weeks after immersion. Results: 1. ${\Delta}E^*$ value of artificial teeth which were soaked in soy sauce and coffee was various according to soaking periods. However there was significant difference between Trubyte $Biotone^{(R)}$ and Physio $Duracross^{(R)}$ in red pepper paste regardless of soaking period(P<.05). 2. Except for 8 weeks of Endura $Anterio^{(R)}$, 4 weeks and 8 weeks of Physio $Duracross^{(R)}$, artificial teeth soaked in red pepper paste regardless of the type had significant difference of ${\Delta}E^*$ value compared with other groups (P<.05). 3. $a^*$, $b^*$ value of Endura $Anterio^{(R)}$ and Trubyte $Biotone^{(R)}$ which were soaked in red pepper paste had significant difference compared with the value of other group(P<.05). Conclusion: Red pepper paste had the greatest effect on color difference of artificial tooth. Physio $Duracross^{(R)}$ showed relatively less color difference than Trubyte $Biotone^{(R)}$ and Endura $Anterio^{(R)}$. But as ${\Delta}E^*$ difference were all less than 3.3, these artificial resin teeth seemed appropriate for clinical use.

• Korean Journal of Poultry Science
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• v.28 no.2
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• pp.99-106
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• 2001

Pathologic changes and distribution of viral antigen as determined by immunohistochemistry were compared among 4-wk-old specific-pathogen free (SPF) chickens inoculated intratracheally with velogenic vis-cerotropic Newcastle disease virus isolated in Korea. Although the pattern of organ involvement and severity of lesion was different among chickens infected with different velogenic viscerotropic Newcastle disease (VVND) viruses, the pathological types of lesion was similar among the chickens. Severe lymphocytic necrosis and depletion were main histologic lesions in the immune related organs such as thymus, Fabricius bursa and spleen. The frequency of IP positive staining was variable depends on the types of tissues but not types of the kinds of VVND viruses infected. Brain, Fabricius bursa, thymus, cecal tonsil and trachea were IP positive with fairly high frequency and spleen, lung, proventriculus, intestine, pancreas, liver, kidney, heart and Harderian gland were with relatively low frequency. These results suggest that histologic evaluation and viral antigen specific immunohistochemical staining methods to determine virus distribution will be useful for pathogenic study of velogenic viscerotropic Newcastle disease virus infection in chicken.

• Korean Journal of Poultry Science
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• v.44 no.1
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• pp.1-9
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• 2017

The objective of the present study was to determine the expression of genes associated with lipopolysaccharide (LPS)-induced stressor in two breeds of chickens: the Korean native chicken (KNC) and the White Leghorn chicken (WLH). Forty chickens per breed, aged 40 weeks, were randomly allotted to the control (CON, administered the saline vehicle) and LPS-injected stress groups. Samples were collected at 0 and 48 h post-LPS injection, and total RNA was extracted from the chicken livers for RNA microarray and quantitative real-time polymerase chain reaction (qRT-PCR) analyses. In response to LPS, 1,044 and 1,193 genes were upregulated, and 1,000 and 1,072 genes were downregulated in the KNC and WLH, respectively, using a ${\geq}2$-fold cutoff change. A functional network analysis revealed that stress-related genes were downregulated in both KNC and WLH after LPS infection. The results obtained from the qRT-PCR analysis of mRNA expression of heat shock 90 (HSP90), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), activating transcription factor 4 (ATF4), sterol regulatory element-binding protein 1 (SREBP1), and X-box binding protein 1 (XBP1) were confirmed by the results of the microarray analysis. There was a significant difference in the expression of stress-associated genes between the control and LPS-injected KNC and WLH groups. The qRT-PCR analysis revealed that the stress-related $HSP90{\alpha}$ and HMGCR genes were downregulated in both LPS-injected KNC and WLH groups. However, the HSP70 and $HSP90{\beta}$ genes were upregulated only in the LPS-injected KNC group. The results suggest that the mRNA expression of stress-related genes is differentially affected by LPS stimulation, and some of the responses varied with the chicken breed. A better understanding of the LPS-induced infective stressors in chicken using the qRT-PCR and RNA microarray analyses may contribute to improving animal welfare and husbandry practices.

• Korean Journal of Food Science and Technology
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• v.45 no.6
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• pp.714-720
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• 2013

We investigated the brewing and fermenting characteristics of makgeolli produced from high-yielding rice varieties. We used the high-yielding indica rice varieties, Anda and Dasan 1, and the japonica varieties, Deuraechan and Boramchan. Our results showed that the rice protein level was the highest in makgeolli produced from Anda ($7.5{\pm}0.2%$), while the amylose level was the lowest in makgeolli produced from the mid- to late-maturing japonica varieties (Deuraechan, $18.9{\pm}0.7%$; Boramchan, $18.9{\pm}1.4%$). Samples of makgeolli produced from Anda, Deuraechan, and Boramchan by using the Ipguk (Koji) method had an alcohol content of 16.6-17.4% on completion of fermentation. By contrast, makgeolli produced from Dasan 1 had an alcohol content of 14.3%; further, the makgeolli differed significantly in the sensory test and was scored as excellent regarding comprehensive preference. For makgeolli produced by using the uncooked rice fermentation method, samples produced from the indica varieties, Anda and Dasan 1, had lower alcohol contents (17.2% and 17.0%, respectively) and higher total acidity levels (0.33% and 0.31%, respectively) than did samples produced from the japonica varieties, Deuraechan and Boramchan (0.28% for both). In the sensory test, samples produced from Anda and Dasan 1 performed significantly better regarding scent, swallowing, and comprehensive preference.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.7
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• pp.7-14
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• 2009

In this paper, the effects of annealing conditions on the structural ((002) intensity, FWHM, d-spacing, grain size, (002) peak position), optical (UV peak, UV peak position) and electrical properties (carrier concentrations, resistivity, mobility) of ZnO films were investigated. ZnO films were deposited onto SiO$_2$/si substrates by RF magnetron sputtering from a ZnO target. The substrate was not heated during deposition. ZnO films were annealed in temperature ranges of $500\sim650^{\circ}C$ in the O$_2$ flow for 5$\sim$20 min. The film average thicknesses were in the range of 291 nm. The surface morphologies and structures of the samples were characterize by SEM and XRD, respectively. The optical properties were evaluated by photoluminescence (PL) measurement at room temperature (RT) using a He-Cd 325 nm laser. As the annealing temperature and time vary, the following relations were also observed: (1) proportional relationships among UV intensity (002) intensity, and grain size exist, (2) UV intensity is inversely proportional to FWHM, (3) there is no special relationship between UV intensity and electron carrier concentrations, (4) d-spacing is inversely proportional to (002) peak position, (5) UV peak position in the range of 3.20$\sim$3.24 eV means that ZnO films have a n-type conductivity which was consistent with that obtained from the electrical property, (6) the optimal conditions for the best optical and structural characteristics were found to be oxygen fraction, (O$_2$/(O$_2$+Ar)) of 0.2, RF power of 240W, substrate temperature of RT, annealing condition of 600$^{\circ}C$ for 20 min, and sputtering pressure of 20 mTorr.

• Journal of the Korean earth science society
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• v.28 no.2
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• pp.169-178
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• 2007

In this research we diagnosed the actual status of the 7th National science elective curriculum and suggested a way to select and organize the content of the new science elective curriculum. The first science education reform was grounded in the structuralism where the structure of discipline was valued above everything else. On the other hand, the second science education reform suggested alternative interpretations of students' opportunity to learn, putting a brake on the structuralist thinking. According to the survey result, the majority of the science elective courses are in need for revision because the contents are overcrowded, too difficult in light of students' learning readiness, failed to draw students' interest in science, and are overlapped and repeated among the 10th grade science, high school science I and II. In particular, Earth Science II and physics II are the most unfavorable courses among students. Thus, we recommended a fundamental change be made in the new curriculum in addition to the optimization of the content. In this paper, we suggested 'topic-centered content organization' for the science elective course I, i.e., Physics I, Chemistry I, Biology I and Earth Science I that is designed for both science track and non-science track students. Since curriculum provides students with an 'opportunity to learn', a curriculum study should focus on what the 'opportunity to learn' is that students ought to be offered. Based on the result of this study, we recommended one way to select and organize the content of high school elective curriculum.

• Journal of Yeungnam Medical Science
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• v.15 no.1
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• pp.97-113
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• 1998

The sympathoadrenal system plays an important role in homeostasis in widely varing external environments. Conflicting findings, however, have been reported on its response to hypoxia. We investigated the effect of hypoxia on the sympathoadrenal system in dogs under halothane anesthesia by measuring levels of circulating catecholamines in response to graded hypoxia. Ten healthy mongreal dogs were mechanically ventilated with different hypoxic gas mixtures. Graded hypoxia and reoxygenation were induced by progressively decreasing the oxygen fraction in the inhalation gas mixture from 21%(control) to 15%, 10% and 5% at every 5 minutes, and then reoxygenated with 60% oxygen. Mean arterial pressure, central venous pressure and mean pulmonary arterial pressure were measured directly using pressure transducers. Cardiac output was measured by the thermodilutional method. For analysis of blood gas, saturation and content, arterial and mixed venous blood were sampled via the femoral and pulmonary artery at the end of each hypoxic condition. The concentration of plasma catecholamines was determined by radioenzymatic assay. According to the exposure of graded hypoxia, not only did arterial and mixed venous oxygen tension decreased markedly at 10% and 5% oxygen, but also arterial and mixed venous oxygen saturation decreased significantly. An increased trend of the oxygen extraction ratio was seen during graded hypoxia. Cardiac output, mean arterial pressure and systemic vascular resistance were unchanged or increased slightly. Pulmonary arterial pressure(PAP) and pulmonary vascular resistance(PVR) were increased by 55%, 76% in 10% oxygen and by 82%, 95% in 5% oxygen, respectively(p<0.01). The concentrations of plasma norepinephrine, epinephrine and dopamine increased by 75%, 29%, 24% in 15% oxygen and by 382%, 350%, 49% in 5% oxygen. These data suggest that the sympathetic nervous system was activated to maintain homeostasis by modifying blood flow distribution to improve oxygen delivery to tissues by hypoxia, but hemodynamic changes might be blunted by high concentration of nitrous oxide except PAP and PVR. It would be suggested that hemodynamic changes might not be sensitive index during hypoxia induced by high concentration of nitrous oxide exposure.

• The Korean Journal of Nuclear Medicine Technology
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• v.15 no.1
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• pp.3-9
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• 2011

Purpose: Generally dual energy X-ray absorptiometry has been used for the purpose of evaluation of osteoporosis and treatment. Recently the interest of obesity came to be high and body percent fat test is increasing. Existing measure of body fat have to scan the whole body can be evaluated, but only lumbar spine and hip measurements was assumed to be whole body fat as well as improving the software. It tries to check whether the part measured value not being whole body measurement has the validity or not compared with the value calculated with the method that it is different, it forgives through a correlation with a (BIA) and (BMI). Materials and Methods: In 2010, the body percent fat was measured among the examinee coming to the Asan Medical Center public health care center from March till August against 90 females more than 40 years old through (DXA) and BIA. BMI utilized the value which wrote an hight and weight measured through the body measuring instrument in the examinee information and is automatically calculated. In addition, it classified as the low weight ($13-18.5kg/m^2$), normal ($18.5-25kg/m^2$), and corpulence ($25-30kg/m^2$) based on BMI and so that it could check whether there was the difference according to the weight or not BMI and BIA and correlation between DXA were analyzed in each group. The statistical program for the analysis used SPSS 12.0. Results: The comparison of DXA at 3 which it divides into the low weight and normal and corpulence groups and BIA did not show the difference noted statistically in all groups and the between group comparison was exposed to do not have a meaning. The body percent fat measured by the correlation analysis result DXA at the state that it doesn't divide into the group showed the high correlation (r=0.908, p0.01) noted statistically compared with BMI and showed the high correlation noted statistically in a comparison with BIA (r=0.927, p0.01). Conclusion: It confirmed that the whole body percent fat presumed from the part bone density measurement showed the excel correlation compared with BIA and BMI and information is high. There is still no clear standard about the presumed whole body percent fat and it is difficult to evaluate the fat evaluation by the bone mineral density measurement. However, it is determined that the information offering which is more objective through the comparative study with the body percent fat which is very efficient and in that it can obtain till the information about a fat as well as diagnosis of the osteoporosis through the bone density checkup is measured by the afterward telegraph bone density checkup and is clinically useful is possible.