• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.210-210
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• 2010

저항 구조를 가진 유기 쌍안정성 소자는 비휘발성 기억 소자 중에서 구조가 간단하고 제작비용이 저렴하며 플렉시블이 용이한 장점 때문에 많은 연구가 진행되고 있다. 유기물/무기물 복합재료를 사용한 유기 쌍안정성 소자 제작에 대한 연구는 많이 진행되어 왔지만, 넓은 에너지 밴드 갭을 가진 $SnO_2$ 나노 입자가 삽입된 고분자 박막을 기반으로 제작한 유기 쌍안정성 소자에 대한 연구는 상대적으로 미흡하다. 본 연구에서는 Poly(methyl methacrylate) (PMMA) 박막 안에 분산된 $SnO_2$ 나노 입자를 사용하여 제작한 유기 쌍안정성 소자의 전기적인 특성을 관찰하였다. 소자를 제작하기 위해 나노 입자의 전구체인 Tin 2-ethylhexanoate (95%) 2.4 mmol을 dibutyl ether (99.3%) 10 ml에 용해시킨 후, 용매열 화학적 방법을 사용하여 용매 안에서 $SnO_2$ 나노 입자를 합성하였다. 용매 안에 들어있는 1 wt%의 $SnO_2$ 나노 입자와 100 mg의 PMMA를 2 ml의 클로로벤젠에 용해하여 고분자 용액을 제작하였다. 하부 전극 역할을 하는 indium tin oxide가 증착된 유리 기판 위에 고분자 용액을 스핀 코팅하고, 열을 가해 용매를 제거하여 $SnO_2$ 나노 입자가 분산되어 있는 PMMA 박막을 형성하였다. 그 위에 Al 전극을 증착하여 기억 소자를 완성하였다. 제작된 유기 쌍안정성 소자의 전류-전압 (I-V) 측정 결과에서는 동일한 전압에서 서로 크기가 다른 전류가 흐르는 I-V 곡선의 히스테리시스 특성이 나타났다. 그러나 $SnO_2$ 나노 입자가 없는 PMMA 박막으로 형성된 유기 쌍안정성 소자에서는 I-V 곡선의 히스테리시스 특성이 나타나지 않았다. 따라서 PMMA 박막 안에 삽입된 $SnO_2$ 나노 입자가 유기 쌍안정성 소자의 메모리 효과에 결정적인 영향을 준 것을 알 수 있었다. 전류-시간 측정 결과에서는 소자의 ON/OFF 비율이 시간에 따라 큰 변화 이 없이 1000 사이클 이상 지속적으로 유지 하고 있음을 보여 줌으로써 유기 쌍안정성 소자를 장시간 사용할 수 있음을 나타내 주었다.

• The Korean Journal of Food And Nutrition
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• v.6 no.4
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• pp.255-267
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• 1993

This study was performed to investigate the correlations among physical anthropometric measurement, diet intakes, physical fitness test, and serum lipids in eight sedentary women(control group), and twenty seven exercising women(aerobic groups), aged 35~45 years. The results of the study are as follows : 1) systolic blood pressure(SBP) and diastolic blood pressure(DBP) of aerobic groups were lower than serf entary. Pulse rate was decreased according to the length of aerobic periods. Muscular endurance and jump power of all subjects were stronger than standard range, and those of aerobic exercising groups were stronger than control group. Muscular power of the upper half of the body In all subjects were lower than standard range. 2) Daily calorie intakes of all subjects were in the ring: of recommended dietary allowances (RDA) for Koreans. But daily protein Intakes were higher than RDA. daily cholestrol intakes of all subjects were slightly less than 200~300 mg: which is normal consumption of Koreans. 3) There was a significant positive correlation between serum 7G and daily protein intakes. It was considered that excessive protein intake converted to serum 7G. There was not a significant correlation between serum TC and dietary TC. Therefore, dietary TC seemed to have not much effect on serum TC. Physical fitness was negatively related to serum TG, TC, LDL-C, but positively related to HDL-C, HDL-C /TC. It was found that the serum lipids could be changed better according to improving the physical fitness. There were significant positive correlations between SBP and serum TC, LDL-C. (According to this results), the higher SBP, the higher serum TC, LDL-C tended to be. There was a significant positive correlations between sit up and weightloss nth exercise r=0.7(p<0.001), push ups and weightless with exercise r=0.5(p<0.001). It was considered that muscle strength could be improved according to the weightloss. 4) The purpose of exercise in aerobic groups was rather promoting health than reducing body fatness. Most of al1 subjects (83.2%) drank caffeine-contained beverage therefore, we should concern about that absorption of Fe could be Interrupted and blood pressure could be elevated by caffeine.

• YAKHAK HOEJI
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• v.42 no.1
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• pp.59-69
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• 1998

To increase the solubility of quercetin, which is a practically insoluble flavonoid of Ginkgo biloba leaf, the effects of nonaqueous vehicles. Their cosolvents, water-sol uble polymers and modified cyclodextrins (CDs) were observed. Polyethylene glycols, diethyleneglycol monoethyl ether, and their cosolvents with water showed a good solvency toward quercetin. Also the aqueous solutions of povidone, copolyvidone and Cremophor RH 40 was effective in solubilizing quercetin. Complex formation of quercetin with ${\beta}$-cyclodextrin (${\beta}$-CD), dimethyl-${\beta}$-cyclodextiin (DMCD), 2-hydroxypropyl-${\beta}$-cyclodextrin (HPCD) and ${\beta}$-cyclodextrin sulfobutyl ether (SBCD) in water was investigated by solubility method at $37^{\circ}C$. The addition of CDs in water markedly increased the solubility of quercetin with increasing the concentration. AL type phase solubility diagrams were obtained with CDs studied. Solubilizaton efficiency by CDs was in the order of SBCD >> DMCD > HPCD > ${\beta}$-CD. The dissolution rates of quercetin from solid dispersions with copolyvidone, povidone and HPCD were much faster than those of drug alone and corresponding physical mixtures, and exceeded the equilibrium solubility (3.03${\pm}1.72{\mu}$g/ml). The permeation of quercetin through duodenal mucosa did not occur even in the presence of enhancers such as bile salts, but the permeation was observed when the mucus layer was scraped off. This was due to the fact that quercetin had a strong binding to mucin ($58.5{\mu}$g/mg mucin). However rutin was permeable to the duodenal mucosa. The addition of enhancer significantly increased the permeation of rutin in the order of sodium glycocholate.

• International Journal of Computer Science & Network Security
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• v.24 no.6
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• pp.200-206
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• 2024

Laser induced breakdown spectroscopy (LIBS) technique has been used for the elemental composition of the soils. In this technique, a high energy laser pulse is focused on a sample to produce plasma. From the spectroscopic analysis of such plasma plume, we have determined the different elements present in the soil. This technique is effective and rapid for the qualitative and quantitative analysis of all type of samples. In this work a Q-switched Nd: YAG laser operating with its fundamental mode (1064 nm laser wavelength), 5 nanosecond pulse width, and 10 Hz repetition rate was focused on soil samples using 10 cm quartz lens. The emission spectra of soil consist of Iron (Fe), Calcium (Ca), Titanium (Ti), Silicon (Si), Aluminum (Al), Magnesium (Mg), Manganese (Mn), Potassium (K), Nickel (Ni), Chromium (Cr), Copper (Cu), Mercury (Hg), Barium (Ba), Vanadium (V), Lead (Pb), Nitrogen (N), Scandium (Sc), Hydrogen (H), Strontium (Sr), and Lithium (Li) with different finger-prints of the transition lines. The maximum intensity of the transition lines was observed close to the surface of the sample and it was decreased along the axial direction of the plasma expansion due to the thermalization and the recombination process. We have also determined the plasma parameters such as electron temperature and the electron number density of the plasma using Boltzmann's plot method as well as the Stark broadening of the transition lines respectively. The electron temperature is estimated at 14611 °K, whereas the electron number density i.e. 4.1 × 10¹⁶ cm^-3 lies close to the surface.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.50 no.4
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• pp.206-215
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• 2024

Objectives: The current in vitro study aimed to assess the effects of ascorbic acid augmented albumin platelet-rich fibrin (AA Alb-PRF) on the wound healing activity of human gingival fibroblasts (HGFs) purported to be a regenerative biomaterial in surgical procedures. Materials and Methods: All assays were performed on three HGF groups, group I: complete media; group II: Alb-PRF, and group III: AA Alb-PRF. Alb-PRF was prepared following the protocol by Fujioka-Kobayashi et al. (2021). For preparation of AA Alb-PRF, 2,500 ㎍ AA was added to the blood pre-centrifugation. All groups were subjected to 3-(4,5-dimethythiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay to estimate cell viability and proliferation, scratch assay for migration (0, 4, 12, and 24 hours) and transwell migration assay for chemotactic migration assessment (24 hours). Outcome variables were optical density (OD) for MTT assay, percentage of wound closure in scratch assay, and number of migrated cells in transwell migration assay. One-way ANOVA for MTT and transwell migration assays and two-way ANOVA for scratch assay with Bonferroni correction were performed with significance set at P<0.05. Results: Cell viability and proliferation (OD: 0.684±0.003 and proliferation: 28%) and wound closure (49.92%±1.62% at 4 hours and 61.39%±0.88% at 12 hours) were significantly higher in group III, while group II demonstrated the maximum number of HGFs migrating across the transwell membrane (9.25±2.49) with P<0.05. Conclusion: HGFs demonstrated a significant increase in viability and proliferation along with rapid wound closure in the presence AA Alb-PRF compared to Alb-PRF alone, indicating additional beneficial effects of AA. Thus, AA Alb-PRF potentiates the wound healing activity of HGFs and could be employed in oral, maxillofacial, and periodontal surgeries as a regenerative biomaterial.

• Journal of Environmental Science International
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• v.23 no.3
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• pp.447-457
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• 2014

The number concentrations, the mass concentrations and the elemental concentrations of $PM_{10}$ have measured at Gosan site in Jeju, Korea, from March 2010 to December 2010. And the correlation and the factor analysis for the number, the mass and the elemental concentrations of $PM_{10}$ are performed to identify their relationships and sources. The average $PM_{10}$ number concentration is observed $246\;particles/cm^3$($35.7{\sim}1,017\;particles/cm^3$) and the average $PM_{10}$ mass concentration is shown $50.1{\mu}g/m^3$($16.7{\sim}441.4{\mu}g/m^3$) during this experimental period. The number concentrations are significantly decreased with increasing particle size, hence the concentrations for the smaller particles less than $2.5{\mu}m$($PM_{2.5}$) are contributed 99.6% to the total $PM_{10}$ number concentrations. The highest concentration of the 20 elements in $PM_{10}$ determined in this study is shown by S with a mean value of $1,497ng/m^3$ and the lowest concentration of them is found by Cd with a mean value of $0.57ng/m^3$. The elements in $PM_{10}$ are evidently classified into two group based on their concentrations: In group 1, including S>Na>Al>Fe>Ca>Mg>K, the elemental mean concentrations are higher than several hundred $ng/m^3$, on the other hand, the concentrations are lower than several ten $ng/m^3$ in group 2, including Zn>Mn>Ni>Ti>Cr>Co>Cu>Mo>Sr>Ba>V>Cd. The size-separated number concentrations are shown positively correlated with the mass concentrations in overall size ranges, although their correlation coefficients, which are monotonously increased or decreased with size range, are not high. The concentrations of the elements in group 1 are shown highly correlated with the mass concentrations, but the concentrations in group 2 are shown hardly correlated with the mass concentrations. The elements originated from natural sources have been predominantly related to the mass concentrations while the elements from anthropogenic sources have mainly affected on the number concentrations of $PM_{10}$.

• Economic and Environmental Geology
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• v.39 no.5 s.180
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• pp.555-566
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• 2006

Major, trace and rare earth elements data of the Cretaceous Jindong granitic rocks were investigated in order to constrain the magma source characteristics and to establish the paleotectonic environment of the southwestern part of the Gyeongsang Basin. Geochemical signatures of the granitic rocks from the study area indicate that all of the rocks have characteristics of calc-alkaline series in the subalkaline field, and progressively shift from metaluminous to peraluminous with differentiation. In the variation diagrams, the overall geochemical features of the granites show systematic variations in major and trace elements. Chondrite normalized REE patterns show generally enriched LREE((La/Yb)c=4.2-12.8) and slight negative to flat Eu anomalies. Rb-Sr isotope data of the Jindong granites show that the whole rock age and Sr initial ratio are $114.6{\pm}9.1Ma$ and 0.70457, respectively. The Sr initial ratio of the Jindong granites is very similar to those of the Creataceous granites from Masan, Kimhae and Busan area($^{87}Sr/^{86}Sr=0.7049-0.707$). These results suggest that the magma have the mantle signature and intruded into the area during the early Cretaceous age. The Jindong granites have higher $Al_{2}O_{3},\;Na_{2}O$, Sr and lower $K_{2}O$, Y concentrations compared with typical calc-alkaline granitic rocks. These adakitic signatures are similar to those of adakitic pluton on Kyushu Island, southwest Japan arc. On the ANK vs. ACNK and tectonic discrimination diagrams, parental magma type of the granites corresponds to I-type, VAG granite. Interpretations of the geochemical characteristics of the granitic rocks favor their emplacement at continental margin during the subduction of Izanagi plate.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.65-75
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• 1996

Sulfate reduction and the precipitation of metal sulfides may have great potential to improve water quality of mine effluents in wetland treatment systems. Laboratory experiments using sulfate reducing bacteria (SRB) and limestone to treat effluents from the abandoned Dalsung tungsten-copper mine show that encouraging results, that have been attributed to sulfate reduction. Fe, Al, Cd, Cu and Zn are reduced to below detection limits with $99{\sim}100%$ metal removal rates, Mn is reduced by at least 90% to below 8.0 mg/l, and the pH is raised from 5.12 to 7.60 after 53 days of experiments. In the staged design, laboratory experiments are initiated to determine what would be reasonable substrate materials for remediation of the mine effluents. A substrate mixture containing 70% oak compost and 30% mushroom compost maintains $0.03{\sim}0.04mM$ of lactate, which provides good condition for the SRB granule. A downflow SRB wetland system is proposed as follows : 1) The lower part of the treatment system consists with a 25 cm thick layer of high quality (above 95% of $CaCO_3$) of limestone; 2) The geotextile (geonet) is recommended to be spread on the limestone bed to prevent clogging the limestones with the substrates; 3) The mixture of substrates with 70% oak and 30% spent mushroom composts, and SRB granules overlain on top of the geonet with 25 cm height. The sizes of the passive treatment systems are calculated according to metal loading and permeability criteria : 1) $220m^3$ ($15{\times}15{\times}1m$) for -1 level effluents; 2) $28m^3$ ($5.3{\times}5.3{\times}1m$) for -2 level; and 3) $2700m^3$ ($52{\times}52{\times}1m$) for the -3 level. The -3 level system needs to be broken down into 5 to 15 cells.

• Childhood Kidney Diseases
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• v.7 no.2
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• pp.166-173
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• 2003

Purpose : The cause and pathogenesis of $Henoch-Sch\"{o}nlein$ purpura has been studied for many years but the results are disappointing. Recently the hypothesis that abnormalities involving the glycosylation of the hinge region of immunoglobulin Al(IgAl) may have an important role in the pathogenesis of $Henoch-Sch\"{o}nlein$ purpura is being approved. $Henoch-Sch\"{o}nlein$ purpura is the most common vasculitis Ihat affects children and the prognosis is good. But if kidney invovement occurs, the course may be chronic and troublesome. So we evaluated children with $Henoch-Sch\"{o}nlein$ purpura especially from the point of epidemiology and clinical manifestations. Methods : Investigation of 124 children who were diagnosed with $Henoch-Sch\"{o}nlein$ purpura at Inje University Ilsan Paik Hospital from December 1999 to July 2003 was performed retrospectively through chart review. Efforts were made to get informations about the profile, epidemiology, clinical manifestations, progress of the disease and recurrence rate of patients. Results : The patients were 69 boys and 55 girls, with a mean age of $6.1{\pm}2.7$ years at the time of data collection. The male to female ratio was 1.25 : 1. The occurrence rate was much higher in autumn(from September to November, 31.5%) and winter(from December to February, 28.2%) than in spring and summer, with a peak in November. Joint involvement was shown in 66.9% of patients mostly on the foot/ankle(75.9%), knee(39.8%). Seventy(56.5%) out of 124 patients had abdominal pain and 10 patients(8.1%) showed bloody stools. Renal involvement was observed in 24 patients(19.4%) after 21.1 days on the average. IgA was elevated in 10 of 21 patients(47.6%). $C_3$ and $C_4$ levels were normal in 40 of 49 patients (81.7%) and 47 of 48 patients(97.9%), respectively Antistreptolysin-O(ASO) titer was elevated over 250 Todd units in 29 of 62 Patients(46.8%). Mycoplasma antibody titer was elevated in 21 of 49 patients(42.9%) equal or greater than 1:80. Radiologic studies were peformed in 23 patients. Seven patients(30.4%) showed bowel wall thickening and one of them received intestinal resection and anastomosis operation due to terminal ileum necrosis. Eighty four patients took steroid 1.4 mg/kg/day in average. Recurrence rate was 2.5 in 37 patients(29.8%). Conclusion : $Henoch-Sch\"{o}nlein$ purpura in childhood appears most in about 6 years of age. The occurrence rate is much higher in autumn and winter relatively. Diagnosis can be made through the perspective history taking and the inspection of clinical manifestations, but the laboratory findings are not of great help. A small portion of the patients might show abdominal pain or arthritis before purpura develops, therfore various diagnosis can be made. Radiologic evaluation should be performed to avoid surgical complications in cases accompanying abdominal pain, and long term follow up should be needed especially in patients suffering from kidney involvement. In about 30% of the patients $Henoch-Sch\"{o}nlein$ purpura would recur. Steroid can be used safely without side effects.

• The Journal of Pediatrics of Korean Medicine
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• v.20 no.1
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• pp.241-255
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• 2006

Objective : Allergic Inflammation is related with secretion of Cytokine. This study was performed to examine the effects of Woobangja on anti-allergic inflammation. Method : While macrophage 264.7cells was chosen as a normal group a control group was classified into three groups. One was stimulated with LPS. and another was pretreated with Woobangja for 1 hour. The third was pretreated with gydrocortisone for 1 hour. After the pretreatment, macrophage were incubated with lipopolysaccharide(LPS) 100 ng/ml for 12h and media collected and $TNF-{\alpha}$, IL-6, $IL-1{\beta}$, IL-10 concentration in supernatants were measured each by Enzyme linked immuno-sorbent assay. Woobangja were used $50\;{\mu}g/ml$, $100\;{\mu}g/ml$, $250\;{\mu}g/ml$, $500\;{\mu}g/ml$, 1 mg/ml. Hydrocortisones were used respectively $10^{-8}\;M$,$10^{-7}\;M$,$10^{-6}\;M$,$10^{-5}\;M$,$10^{-4}\;M$. Results : Woobangja showed inhibitory effect on $TNF-{\alpha}$ by LPS-stimulated macrophage 264.7. The inhibitory effect was most significant in 1mg/ml(p<0.01), and has increased according to the number of doses. Woobangja also showed inhibitory effect on IL-10 by LPS-stimulated macrophasg 264.7. The inhibitory effect was most significant in $100\;{\mu}g/ml$, and was not in a dose-dependent manner as Hydrocortisone group. Woobangja and Hydrocortison showed contrary effect on $IL-1{\beta}$ in al five concentration(p<0.01), and at the lowest concentration ($50\;{\mu}g/ml$) the level of $IL-1{\beta}$ was the lowest. On the other hand hydrocortison was observed to have inhibitory effect on $IL-1{\beta}$ in all five concentration(p<0.01). IL-6 was inhibited by hydrocortison in a roughly dose-dependent manner, but was not inhibited by Woobangja. On the contrary Woobangja obviously increased the expression of $IL-1{\beta}$ in all five concentration(p<0.01), but it was not related with concentrations. Conclusion : 1. Woobangja does significantly inhibit the expression of $TNF-{\alpha}$ by LPS-stimulated macrophage 264.7. 2. Woobangja does significantly increse the expression of IL-6 by LPS-stimulated macrophage 264.7. 3. Woobangja does significantly increse the expression of $IL-1{\beta}$ by LPS-stimulated macrophage 264.7. 4. Woobangja does significantly inhibit the expression of IL-10 by LPS-stimulated macrophage 264.7. 5. Woobangja is observer to have anti-allergic inflammatory effect through inhibiting inflammatory cytokine.