• Journal of Chest Surgery
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• v.37 no.4
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• pp.307-312
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• 2004

With the development of cardiac surgical technique, we need more prosthetic materials for repairing the intra- and extracardiac defects. Although bovine pericardial bioprosthesis treated with glutaraldehyde (GA) solution is one of the most popular materials, it has a drawback of later calcific degeneration. The purpose of this study is to investigate the effectiveness of several materials and methods in reducing the calcific degeneration of bovine pericardium. Material and Method: Forty square-shaped pieces of bovine pericardia were fixed in 0.625% GA solution with 4 g/L MgCl$_2$ㆍ6$H_2O$ as a control group (group 1). Other 40 pieces pre-treated with 1 % SDS(group 2) and 40 pieces post-treated with 8% glutamate (group 3) and 2% chitosan (group 4) were also fixed in the same GA solution. Other 40 pieces pre-treated with 1% SDS and post-treated with 8% glutamate and 40 pieces post-treated with 2% chitosan were also fixed in the same GA solution (group 5, 6). The pericardial pieces were implanted into the belly of 40 Fisher 344 rats subdermally and were extracted 1 month, 2 months, 3 months, and 6 months after the implantation. With an atomic absorption spectrophotometry, we measured the calcium amount deposited and examined the tissue with microscope. Result: The calcium deposition in 1 month was less in group 2, 5, 6 than that in group 1 (p＜0.05). It was most prominent in group 5 (p＜0.01). This finding continued in 2 month. In 3 month, the calcium deposition was less in group 3 and 4 as well as group 2, 5, and 6 than in group 1. In 6 month, the calcium deposition in group 2, 3, 4, 5, and 6 was less than that in group 1 and the difference was more than that of 1, 2, and 6 month. The microscopic calcium deposition was also less in group 2 and 5. Calcium deposition developed in the whole layer of pericardium, beginning with the surrounding the collagen fiber and progressing inwardly. Conclusion: Pre-treatment with SDS, post-treatment with glutamate or chitosan, and SDS pre-treatment and post-treatment with glutamate or chitosan were effective in reducing the calcium deposition in bovine pericardium. Moreover, the combined method of SDS pre-treatment and glutamate post-treatment was more effective than other methods.

• Journal of the Korean Vacuum Society
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• v.10 no.3
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• pp.374-379
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• 2001

We have investigated the annealing effects on the optical properties of InAs quantum dots(QDs) capped with InGaAs(sample QDl), where InGaAs layer was deposited by opening Gallium, Arsenic, Indium and Arsenic shutters alternately with 3 periods, grown by molecular beam epitaxy. The emission wavelength of the sample of InAs QDs capped by GaAs barriers was observed to be blue-shifted as the annealing temperature was increased. On the other hand, the photoluminescence(PL) peak position of sample QD1 was observed to be red-shifted at the annealing temperature of up to $600^{\circ}C$ and, then, it was found to be blue-shifted at temperatures ranging from 700 to $800^{\circ}C$. The full width at half maximum values of sample QD1 subjected to annealing treatments show different behavior compared to typical InAs quantum dot structures.

• Proceedings of the Materials Research Society of Korea Conference
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• 2003.11a
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• pp.154-154
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• 2003

A stoichiometric mixture of evaporating materials for CuGaSe2 single crystal thin films was prepared from horizontal electric furnace. Using extrapolation method of X-ray diffraction patterns for the polycrystal CuGaSe2, it was found tetragonal structure whose lattice constant at and co were 5.615 ${\AA}$ and 11.025 ${\AA}$, respectively. To obtain the single crystal thin films, CuGaSe2 mixed crystal was deposited on thoroughly etched semi-insulating GaAs(100) substrate by the hot wall epitaxy (MWE) system. The source and substrate temperatures were Slot and 450$^{\circ}C$, respectively. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (UXD). The carrier density and mobility of CuGaSe2 single crystal thin films measured with Hall effect by van der Pauw method are 5.0l${\times}$10$\^$17/ cm$\^$-3/ and 245 $\textrm{cm}^2$/V$.$s at 293K, respectively. The temperature dependence of the energy band gap of the CuGaSe2 obtained from the absorption spectra was well described by the Varshni's relation, Eg(T) = 1.7998 eV - (8.7489${\times}$10$\^$-4/ eV/K)T$^2$/(T + 335 K. After the as-grown CuGaSe2 single crystal thin films was annealed in Cu-, Se-, and Ca-atmospheres, the origin of point defects of CuGaSe2 single crystal thin films has been investigated by the photoluminescence(PL) at 10 K The native defects of V$\_$CU/, V$\_$Se/, Cu$\_$int/, and Se$\_$int/ obtained by PL measurements were classified as a donors or accepters type. And we concluded that the heat-treatment in the Cu-atmosphere converted CuGaSe2 single crystal thin films to an optical n-type. Also, we confirmed that Ga in CuGaSe2/GaAs did not form the native defects because Ga in CuGaSe2 single crystal thin films existed in the form of stable bonds.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.37 no.3
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• pp.14-19
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• 2000

Free-standing GaN single crystal substrates have been obtained by growing thick GaN epitaxial layers on (0001) sapphire substrates using hydride vapor phase epitaxy (HVPE) method. After growing the GaN thick film of 200 ${\mu}{\textrm}{m}$, a free-standing GaN with a size of 10 mm $\times$10 mm were obtained by mechanical polishing process to remove sapphire substrate. Crack-free GaN substrates have been obtained by GaCl pre-treatment prior to the growth of GaN epitaxial layers. Properties of free-standing GaN substrates have been compared with those of lateral epitaxial overgrowth (LEO) GaN films by double-crystal x-ray diffraction (DC-XRD), cathodoluminescence (CL) and photoluminescence (PL) measurements.

• Journal of Plant Biology
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• v.20 no.2
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• pp.91-101
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• 1977

Using barley seeds (Hordeum sativum Jess, var.), the influences of gibberellic acid (GA) and indole-3-acetic acid(IAA) on the amylase synthesis and that of the nucleic acid metabolism were investigated. 1. With the deembrynized barley seeds, the increase of amylase treated with a $10^{-5}M$ of GA and the decrease of amylase treated with $10^{-5}M$IAA were matched by a proportionate increase and decrease in the amount of RNA. The influence of the hormones on the RNA synthesis has appeared immediately after the treatment but on the amylase synthesis it has appeared 8 hours later. But no influence on the DNA synthesis was observed on both hormones. 2. The amylase from deembryonized barley seeds treated with GA and IAA have been fractionated by gel filteration on Sephadex G-100. The amylase components showed four fractions on both enzymes treated with GA and IAA. Fraction I(FI) was differed from fraction Ⅵ(FIV) in Km value and the effects of temperature, pH and metal ions. On the basis of their emzymatic properties, it was considered that the FI was $\beta$-amylase and FIV was $\alpha$-amylase. The influences of GA and IAA on each fractions appeared to be similar but on the amylase units per souble protein, IAA inhibited the production of amylase FIV while it promoted that of amylase FI. 3. An experiment was conducted to determine whether IAA inhibits GA-promoted amylase synthesis competitively or non-competitively. Using a Lineweaver-Burk plot, it was clear that IAA was acting in a non-competitive fashion. From this, IAA was probably not competing with GA at the same site, but it was acting at some other site which resutled in partial blocking of the action of GA on the amylase synthesis.

• Journal of Biomedical Engineering Research
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• v.22 no.6
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• pp.511-518
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• 2001

In vitro corrosion resistance of the commercially used 76.5wt.%Pd-17.6%Cu-7.2%Ga and 77.3%Pd-6.0%Ga dental Prostheses high-Palladium system alloys in cast, degassing and porcelain-firing heat treatment conditions were evaluated by the potentiodynamic polarization technique in the de-aerated 0.9%NaCl and a modified Fusayama electrolyte. From the corrosion rate experimental results, we found that there is a small difference in the corrosion resistance depending on the microstructure. However. it was so small that there is no significant problem as a dental material. The 77.3%Pd-6.0%Ga showed better corrosion resistance than the 76.5%Pd-11.6%Cu-7.2%Ga dental Prostheses high-palladium system alloys. These experimental observations in 76.5%Pd-11.6%Cu-7.2%Ga alleys are mainly due to a rapid quenching and Cu in the alloy which accelerate the eutectic reaction with a segregation and Precipitates in the microstructure. On the ocher hand, 77.3%Pd-6.0%Ga alloys, which are solid-solution matrix, show much better col·lesion resistance compared with that of 76.5%Pd-11.6%Cu-7.2%Ga alloys.

• Journal of Applied Biological Chemistry
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• v.53 no.3
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• pp.147-153
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• 2010

$\beta$-glycyrrhetinic acid (GA), the active principle of licorice (Glycyrrhiza glabra L.) has been reported to exhibit anti-inflammatory properties in different animal models. In this study, the effects of GA on the production of inflammatory mediators including tumor necrosis factor (TNF)-$\alpha$, interleukin (IL)-6, nitric oxide (NO), and prostaglandin E (pGE)-2 were examined in RAW 264.7 cells in vitro. Furthermore, to elucidate a possible mechanism for the inhibitory effect of GA on the production of TNF-$\alpha$, it was investigated whether the treatment of GA affects the I-${\kappa}B{\alpha}$ degradation and subsequent nuclear translocation of NF-${\kappa}B$. Various inflammatory responses were induced in the culture system by treating with a lipopolysaccharide (LPS). GA showed anti-inflammatory activities in dose-dependant manner with $IC_{50}$ of $5.4{\mu}M$ by inhibiting the production of TNF-$\alpha$ in RAW 264.7 cells. In addition, the treatment of GA blocked both I-${\kappa}B{\alpha}$ degradation and the nuclear translocation of NF-${\kappa}B$ from cytosol to nucleus. However, it did not affect the production of IL-6, NO, and PGE-2, implying the direct blocking of the production of TNF-$\alpha$ resulting from both the I-${\kappa}B{\alpha}$ degradation and the nuclear translocation of NF-${\kappa}B$. This finding might provide the underlying mechanism to explain the reported anti-inflammatory activities of GA in animal models.

• Korean Journal of Agricultural Science
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• v.10 no.2
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• pp.242-248
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• 1983

The effects of light source, plant growth regulators (GA, BA, ABA), and sodium hypochlorite (4% Cl, SH) on germination of 'G rand Rapid' lettuce (Lactuca sativa L.) seed were studied. Seed did not germinate under the conditions of dark and blue light. The treatment of GA or BA did not promote on germination under dark or blue light. The germination percentage under red light was very high, it was similar to the condition of white light. ABA inhibited lettuce seed germination. Although ABA was treated, BA 10ppm treatment was moderately effective under white light condition and BA 10ppm or 50ppm combined with GA 50ppm were also effective on seed germination under dark condition. Presoaking in sodium hypochlorite solution induced germination of lettuce seed in any condition of dark or white light. The optimum presoaking time in sodium hypochlorite solution was twenty min.

• Journal of Acupuncture Research
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• v.24 no.6
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• pp.207-213
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• 2007

Objectives : This study was designed to investigate the effect of SAAM-Acupuncture and GamigungguitangGaNokyong(GMGGTN) on Ankle Fracture. Methods : SAAM-Acupuncture was administered once daily. The following points were selected: $SP_3$(太白), $LU_9$(太淵), $LI_{11}$(曲池). After short leg casting, GMGGTN was taken 3 times per a day from March 28th to April 30th. We evaluated the patient using the Visual Analogue Scale(VAS) and Ankle Range of Motion(ROM). Results : After about 3 weeks of treatment, the patient's short leg cast was removed a week earlier than expected and the patient could walk without crutches and physical therapy. Their VAS changed from 10 to 1. And after added treatment for 2 weeks, there was no pain and limitation of ROM. Conclusions : According to the results, SAAM-Acupuncture and GMGGTN may have rapid effects on ankle fractures. But further studies are required to confirm this effect.

• Journal of the Korean Society for Heat Treatment
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• v.35 no.2
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• pp.51-56
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• 2022

In this study, we controlled the shape of a carbon layer on gallium oxide templates. Gallium oxide layers were deposited on sapphire substrates using mist chemical vapor deposition. Subsequently, carbon layers were formed using radio frequency plasma chemical vapor deposition. Various shapes of carbon structures appeared according to the fraction of methane gas, used as a precursor. As methane gas concentration was adjusted from 1 to 100%, The shapes of carbon structures varied to diamonds, nanowalls, and spheres. The growth of carbon isotope structures on Ga₂O₃ templates will give rise to improving the electrical and thermal properties in the next-generation electronic applications.