• Bulletin of the Korean Chemical Society
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• v.35 no.2
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• pp.494-500
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• 2014

Indium-doped zinc oxide nanocrystals (IZO NCs), capped with stearic acid (SA) of different sizes, were synthesized using a hot injection method in a noncoordinating solvent 1-octadecene (ODE). The ligand exchange process was employed to modify the surface of IZO NCs by replacing the longer-chain ligand of stearic acid with the shorter-chain ligand of butylamine (BA). It should be noted that the ligand-exchange percentage was observed to be 75%. The change of particle size, morphology, and crystal structures were obtained using a field emission scanning electron microscope (FE-SEM) and X-ray diffraction pattern results. In our study, the 5 nm and 10 nm IZO NCs capped with stearic acid (SA-IZO) were ligand-exchanged with butylamine (BA), and were then spin-coated on a thermal oxide ($SiO_2$) gate insulator to fabricate a thin film transistor (TFT) device. The films were then annealed at various temperatures: $350^{\circ}C$, $400^{\circ}C$, $500^{\circ}C$, and $600^{\circ}C$. All samples showed semiconducting behavior and exhibited n-channel TFT. Curing temperature dependent on mobility was observed. Interestingly, mobility decreases with the increasing size of NCs from 5 to 10 nm. Miller-Abrahams hopping formalism was employed to explain the hopping mechanism insight our IZO NC films. By focusing on the effect of size, different curing temperatures, electron coupling, tunneling rate, and inter-NC separation, we found that the decrease in electron mobility for larger NCs was due to smaller electronic coupling.

• Advances in Traditional Medicine
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• v.10 no.3
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• pp.155-164
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• 2010

Lycii fructus is the fruit of Lycium chinense Miller and is part of the Solanaceae family. Lycii fructus produces various effects such as hypotensive, hypoglycemic, anti-pyretic, and anti-stress activities. Lycii fructus is known to contain betaine, carotene, nicotinic acid, zeaxanthin, and cerebroside. In the present study, the effects of Lycii fructus aqueous extract on lipopolysaccharide (LPS)-induced inflammation in murine raw 264.7 macrophage cells were investigated. In this study we utilized the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, reverse transcriptionpolymerase chain reaction (RT-PCR), Western blotting, and nitric oxide (NO) detection. Lycii fructus aqueous extract suppressed NO production by inhibiting the LPS-induced expressions of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-$\alpha$) mRNA and iNOS protein in murine raw 264.7 macrophage cells. Also, Lycii fructus aqueous extract suppressed the activation of nuclear factor-kappa B (NF-${\kappa}B$) in the nucleus. These results demonstrated that Lycii fructus aqueous extract causes an anti-inflammatory effect that was likely produced by the suppression of iNOS expression through the down-regulation of NF-$\hat{e}B$ binding activity.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.7 s.361
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• pp.54-61
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• 2007

A variable gain low noise amplifier (VG-LNA) implemented in TSMC 0.18 um process is presented. This VG-LNA is designed of two stage amplifier, and its gain is controlled by the shunt feedback loop composed of a gain control transistor (GCT) and a coupling capacitor in second stage. The channel resistance of GCT in the shunt feedback loop influences the input and output stages of a second stage by the Miller effect. Total gain of the proposed VG-LNA is changed by two factors, the load impedance reduction and the interstage mismatch by controlling the channel resistance of the GCT. Consequently, by adding a shunt feedback with a gain control transistor, this proposed VG-LNA achieves both wide gain tuning range of 37 dB and continuous gain control simultaneously.

• Journal of Periodontal and Implant Science
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• v.30 no.1
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• pp.133-146
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• 2000

Histological studies indicate a tetracycline HCl similar to citric acid to induce connetive tissue repair in animals. When tetracycline HCl was used as a root conditioning agent in humans, there was a trend toward more connective tissue attachment than in root planing alone. The purpose of this study was to evaluate clinical effect of tetracycline HCl in the treatment of gingival recession. 44 teeth in 12 patients with bilaterally gingival recession & Miller classification I, II gingival recession were selected and 22 teeth were treated with 125mg/ml tetracycline HCl , the others was not treated with tetracycline HCl. Gingival recession, pocket depth, clinical attachment level, width of keratinized gingiva were observed at baseline, postoperative 4, 12, 20weeks. Both groups were statistically analyzed by Wilcoxon signed Ranks Test & Wilcoxon's rank sum test(Mann-whitney test) using SPSS program.(5% significance level) The results were as follows: 1........The change of gingival recession, clinical attachment level, keratinized gingiva in both groups were increased significantly at 4, 12, 20 weeks. 2.......The pocket depth exhibited no marked changes throughout the entire investigation in both groups. 3........The change of gingival recession in tetracycline group was increased significantly than control group at 4, 12, 20 weeks and the percentage of root coverage was 93% in tetracycline group and 83% in control group. 4........The change of clinical attachment level, pocket depth, keratinized tissue from baseline to 4, 12, 20 weeks was not differ significanltly in both group.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.873-876
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• 2000

Characteristics of piezoelectric thick films prepared by screen printing method were investigated. The piezoelectric thick films were printed using Pb(Mg,Nb)O$_3$-Pb(Zr,Ti)O$_3$system. The lower electrodes were coated with various thickness of Ag-Pd by screen printing to investigate the effect as a diffusion barrier and deposited with Pt by sputtering on Ag-Pd. The ceramic paste was prepared by mixing powder and binder with various ratios using three roll miller. The fabricated thick films were burned out at 650$^{\circ}C$ and sintered at 950$^{\circ}C$ in the O$_2$condition for each 20, 60min after printing with 350mesh screen. The thickness of piezoelectric thick film was 15∼20 $\mu\textrm{m}$ and the Ag-Pd electrode acted as a diffusion barrier above 3 $\mu\textrm{m}$ thickness. When the lower electrode Ag-Pd was 6 $\mu\textrm{m}$ and the piezoelectric thick films were sintered by 2nd step (650$^{\circ}C$/20min and 950$^{\circ}C$/1h) using paste mixed Pb(Mg,Nb)O$_3$-Pb(Zr,Ti)O$_3$$.$ MnO$_2$+ Bi$_2$O$_3$. V$_2$O$\_$5/ and binder in the ratio of 70:30, the remnant polarization of thick film was 9.1 ${\mu}$C /cm$^2$.

• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.58-63
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• 1996

This experiment was carried out to elucidate the effect of the rain shelter and insect net on the growth and yield in Lycium chinense 'Cheongyang Cultivar'. The yield cultivated at the condition of the rain shelter and insect net were increase $92{\sim}106$ percent as that of nature conditions resulted from better growth and decrease of fruit attacked by anthracnose and injured by Eriophyes kuko. It had not significant between the ventilation and non-ventilation.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.101-101
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• 2010

ZnO shows a direct band gap of 3.37eV, large exciton binding energy (~60 meV), high oxidation ability, high sensitivity to many gases, and low cost, and it has been used in various applications such as transparent electrodes, light emitting diodes (LEDs), gas sensors and photocatalysts. Among these applications ZnO as photocatalyst has considerably attracted attention over the past few years because of its high activities in removing organic contaminants generated from industrial activities. In this research, ZnO nanoparticles were synthesized by spray-pyrolysis method using the zinc acetate dihydrate as starting material at synthesis temperature of $900^{\circ}C$ with concentration varied from 0.01 to 1.0M. The physical and chemical properties of the synthesized ZnO nanoparticles were examined by X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transformation Infrared (FT-IR), and UV-vis spectroscopy. The Miller indices of XRD patterns indicate that the synthesized ZnO nanoparticles showed a hexagonal wurtzite structure. With increased precursor concentration, a primary, secondary particle sizes of ZnO nanoparticles increased by 0.8 to $1.5{\mu}m$ and 15 to 35nm, and their crystallinity was improved. Methyleneblue (MB) solution ($1{\mu}M$) as a test comtaminant was prepared for evaluating the photocatalytic activities of ZnO nanoparticles synthesized in different precursor concentration. The results show that the photocatalytic efficiency of ZnO nanoparticles was gradually enhanced by increased precursor concentration.

• The Korean Journal of Food And Nutrition
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• v.30 no.4
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• pp.841-846
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• 2017

This study investigated the nutritional compositions and physiochemical properties of three domestically cultivated jujube fruits (Boeun, Sangwhang, and Bokjo). Nutrient contents were analyzed by freeze-drying the jujube fruits. The results showed that the proximate compositions of the three jujube cultivars ranged from 7.85~13.52% for moisture, 4.65~5.24% for crude protein, 1.29~2.38% for crude ash, 0.17~1.09% for crude lipid, and 7.66~16.63% for crude fiber. The above proximate contents of jujube cultivars were significantly different. Mineral contents of Al, Fe, Mg, Ca, Na, and K in the three jujube fruits were also determined. Mn, Cu and Zn were not detected in any of the varieties. The content of Al was higher in Sangwhang, while Boeun had higher contents of Ca and K. The total polyphenol, ABTS values, and hypoglycemic effect were slightly higher in Boeun as compared to the other varieties. Taken together, Boeun could be an important source of natural antioxidant as a functional food.

• Journal of Korean Society of Forest Science
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• v.90 no.1
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• pp.139-145
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• 2001

Behavior of Matsucoccus thunbergianae Miller and Park males immediately after emergence from their cocooning site, and meteorological factors affecting the responsiveness of the flying males to synthetic pheromone were studied. On Pinus thunbergii saplings, newly emerged males walked around to locate females. The males lanuched themselves into flight after up to three times of copulation. Without the presence of females, the males took off within five minutes whereas when the females were placed nearby but copulation was artifically prohibited the males did not take off. In a wind tunnel, the presence of female pheromone discouraged male take off. More males were flying in sunny area than in shade, but light intensity had no effect on the responsiveness of males toward the pheromone source. Wind speed was the main meteorological factor that affected the male responsiveness. Most males, after hitting the substrate near pheromone source with various posture, stood on their feet and approached the source.

• Imaging Science in Dentistry
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• v.53 no.1
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• pp.1-9
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• 2023

Purpose: The aim of this study was to evaluate 3-dimensional cone-beam computed tomography (CBCT) images of alveolar bone changes in patients who underwent minimally invasive periodontal surgery-namely, the pinhole surgical technique (PST). Materials and Methods: Alveolar bone height was measured and compared on CBCT images of 254 teeth from 23 consecutive patients with Miller class I, II, or III recession who had undergone PST. No patient with active periodontal disease was selected for surgery. Two different methods were used to assess the alveolar bone changes postoperatively. In both methods, the distance between the apex of the tooth and the mid-buccal alveolar crestal bone on pre- and post-surgical CBCT studies was measured. Results: An average alveolar bone gain >0.5 mm following PST was identified using CBCT(P=0.05). None of the demographic variables, including sex, age, and time since surgery, had any significant effect on bone gain during follow-up, which ranged from 8 months to 3 years. Conclusion: PST appears to be a promising treatment modality for recession that results in stable clinical outcomes and may lead to some level of resolution on the bone level. More long-term studies must be done to evaluate the impact of this novel technique on bone remodeling and to assess sustained bone levels within a larger study population.