• Title/Summary/Keyword: Alkaline material

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The effect of immobilization of heparin and bone morphogenic protein-2 to bovine bone substitute on osteoblast-like cell's function

  • Huh, Jung-Bo;Kim, Sung-Eun;Song, Se-Kyung;Yun, Mi-Jung;Shim, Ji-Suk;Lee, Jeong-Yo;Shin, Sang-Wan
    • The Journal of Advanced Prosthodontics
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    • v.3 no.3
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    • pp.145-151
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    • 2011
  • PURPOSE. This study was performed to investigate the ability of recombinant human-bone morphogenic protein-2 immobilized on a heparin-grafted bone substrate to enhance the osteoblastic functions. MATERIALS AND METHODS. The Bio-$Oss^{(R)}$, not coated with any material, was used as a control group. In rhBMP-2-Bio-$Oss^{(R)}$ group, rhBMP-2 was coated with Bio-$Oss^{(R)}$ using only deep and dry methods (50 ng/mL, 24 h). In heparinized rhBMP-2-Bio-$Oss^{(R)}$ group, dopamine was anchored to the surface of Bio-$Oss^{(R)}$, and coated with heparin. rhBMP-2 was immobilized onto the heparinized- Bio-$Oss^{(R)}$ surface. The release kinetics of the rhBMP-2-Bio-$Oss^{(R)}$ and heparinized rhBMP-2-Bio-$Oss^{(R)}$ were analyzed using an enzyme-linked immunosorbent assay. The biological activities of the MG63 cells on the three groups were investigated via cytotoxicity assay, cell proliferation assay, alkaline phosphatase (ALP) measurement, and calcium deposition determination. Statistical comparisons were carried out by one-way ANOVA test. Differences were considered statistically significant at $^*$P<.05 and $^{**}$P<.001. RESULTS. The heparinized rhBMP-2-Bio-$Oss^{(R)}$ showed more sustained release compared to the rhBMP-2-Bio-$Oss^{(R)}$ over an extended time. In the measurement of the ALP activity, the heparinized group showed a significantly higher ALP activity when compared with the non-heparinized groups (P<.05). The MG63 cells cultivated in the group with rhBMP-2 showed increased calcium deposition, and the MG63 cells from the heparinized group increased more than those that were cultivated in the non-heparinized groups. CONCLUSION. Heparin increased the rhBMP-2 release amount and made sustained release possible, and heparinized Bio-$Oss^{(R)}$ with rhBMP-2 successfully improved the osteoblastic functions.

REINFORCEMENT OF FRACTURE RESISTANCE AFTER APEXIFICATION : CASE REPORT (치근단 형성술 후 약화된 치아의 파절 저항성 보강: 증례보고)

  • Lee, Young-Ho;Park, Ho-Won;Lee, Ju-Hyun;Seo, Hyun-Woo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.39 no.4
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    • pp.397-403
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    • 2012
  • The vitality of immature tooth could be lost by dental caries, trauma and fracture of malformed tooth. The vitality loss might lead to halt of the development of the root. The recommended endodontic treatment for a non-vital immature permanent tooth is apexification. Apexification is a method of inducing apical closure through the formation of mineralized tissue in the apical pulp region. Calcium hydroxide is the material of choice for apexification. Long-term exposure to calcium hydroxide may form the apical hard tissue, but weaken the dentin due to its alkaline nature and thus make the roots more susceptible to fracture. It is important to preserve any weakened tooth, so a permanent restoration is needed to reinforce teeth that are prone to fracture. The purpose of this case report was to describe the treatment for reinforcing immature teeth treated with long-term calcium hydroxide. In these cases, the apexes of teeth were sealed with MTA plugs and the root canals were restored with composite resin and fiber post.

Engineering Performance and Applicability of Eco-Friendly Concrete for Artificial Reefs Using Electric Arc Furnace Slags (전기로 슬래그를 활용한 인공리프용 친환경콘크리트의 공학적 성능 및 적용성)

  • Jo, Young-Jin;Choi, Se-Hyu
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.35 no.3
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    • pp.533-544
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    • 2015
  • Unlike the concrete structure built on land, that exposed to the marine environment is greatly degraded in durability due to the exposure to not only the physical action caused by sea wind, tide, and wave, but also the harsh conditions, including the chemical erosion and freeze-thaw which result from $SO_4{^{2-}}$, $Cl^-$ and $Mg^{2+}$ ions in seawater. In the process of the large scaled construction of submerged concrete structures, of course environmental hazardous substance, such as alkaline (pH) and heavy metals, may be leached. Thus, this issue needs to be adequately reviewed and studied. Therefore, this study attempted to develop a CSA (Calcium Sulfo Aluminate) activator using electric arc furnace reducing slags, as well as the eco-friendly concrete for artificial reefs using electric arc furnace oxidizing slag as aggregate for concrete. The strength properties of the eco-friendly concrete exposed to the marine environment were lower than those of the normal concrete by curing 28 days. This suggest that additional studies are needed to improve the early strength of the eco-friendly concrete. With respect to seawater resistance of the eco-friendly concrete, the average strength loss against 1 year of curing days reached 8-9%. the eco-friendly concrete using high volume of ground granulated blast furnace slags and high specific gravity of electronic arc furnace oxidizing slag demonstrated the sufficient usability as a freeze-thaw resistant material. With respect to heavy metal leaching properties of the eco-friendly concrete, heavy metal substances were immobilized by chemical bonding in the curing process through the hydration of concrete. Thus, heavy metal substances were neither identified at or below environmental hazard criteria nor detected, suggesting that the eco-friendly concrete is safe in terms of leaching of hazardous substances.

Acute Toxicity Evaluation of Loess-sulfur Complex in different pH (황토유황합제의 pH차이에 따른 급성독성평가)

  • Paik, Min-Kyoung;Shim, Chang-Ki;Lee, Je-Bong;Oh, Jin-Ah;Jeong, Mi-Hye;Kim, Doo-Ho;Kim, Min-Jeong;Jee, Hyeong-Jin;Choi, Eun-Ji;Cho, Hyeon-Jo
    • The Korean Journal of Pesticide Science
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    • v.16 no.4
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    • pp.369-375
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    • 2012
  • Loess-sulfur complex has been widely used as an environmental friendly organic materials for insecticides and fungicides in crop cultivation. However, there are high concerns about skin and eye irritation for farm workers due to the high alkaline properties of loess-sulfur complex. The acute toxicity evaluation was conducted with three samples of loess-sulfur complex in different pH (pH 9, 10, 11) in order to supply the evidentiary data for selecting the optimal product among the test materials. The results of acute oral toxicity using rats showed $LD_{50}$ of over 2,000 mg/kg b.w. for all three samples of loess-sulfur complex. The calculated acute dermal $LD_{50}$ of all tested materials was over 4,000 mg/kg b.w.. The Skin and eye irritation indicated that all tested materials have no irritation. Consequently, it was suggested that loess-sulfur complex be low in acute toxicity at all different pH values (pH 9~11).

The Improvement Effect of Fermented Angelica gigas Nakai Powder Against Orotic Acid-induced Fatty Liver in Rats (Orotic acid 유발 흰쥐 지방간 개선에 미치는 발효당귀의 효과)

  • Ahn, Hee-Young;Park, Kyu-Rim;Cho, Young-Su
    • Journal of Life Science
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    • v.24 no.4
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    • pp.411-418
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    • 2014
  • This study was to investigate the potential effects of fermented Angelica gigas Nakai (FAG) at 5% (w/w) levels in Sprague-Dawley strain rats, which were intoxicated with 1% (w/w) orotic acid (OA) for 10 days. The activities of several hepatic enzymes, including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and cholinesterase were increased when OA was treated, but these parameters were significantly decreased by FAG administration. OA treatment induced a significant increase in the thiobarbituric acid reactive substances (TBARS) levels, which was attenuated by FAG administration. Liver nonheme ion was decreased in the OA treatment group and was significantly increased in FAG administration, which suggests that lipid peroxidation contents are inversely correlated with liver nonheme ion content. The glutathione concentration was significantly decreased in the OA treatment group compared with the normal group, but this concentration was significantly increased in the FAG group, and it showed the antioxidant ability of glutathione. Based on these results, fermented Angelica gigas Nakai is a material with significant potential for development into a health food that can improve fatty liver conditions.

Production of Lactulose by Biological Methods and Its Application (생물학적 방법을 통한 기능성 이당 lactulose의 생산과 응용 연구)

  • Kim, Yeong-Su;Kim, Do-Yeon;Park, Chang-Su
    • Journal of Life Science
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    • v.26 no.12
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    • pp.1477-1486
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    • 2016
  • Lactulose (4-O-${\beta}$-D-galactopyranosyl-D-fructose) is a non-digestible synthetic ketose disaccharide which can used in food and pharmaceutical fields due to its useful functions for encephalopathy, chronic constipation, hyperammonemia, etc. Therefore, the lactulose is regarded as one of the most important disaccharides and have been concentrated much interesting as an attractive functional material in the current industry. From this reason, the research related on the production of lactulose has been carried out various academic and industrial research groups. To produce lactulose, two main methods, chemical production and enzymatic production have been used. Commercially lactulose produced by alkaline isomerization of lactose as chemical production method but it has many disadvantages such as rapid lactulose degradation, purification, and waste management. From these reasons, lactulose produced by enzymatic method which solves these problems has been suggested as a proper method for lactulose production. Two different enzymatic methods have been reported as methods for lactulose production. Lactulose can be obtained through hydrolysis and transfer reaction catalyzed by a ${\beta}$-galactosidase which requires fructose as co-substrate and exhibits a low conversion. Alternatively, lactulose can be produced by direct isomerization of lactose to lactulose catalyzed by cellobiose 2-epimerase which requires lactose as a single substrate and achieves a high lactulose yield. This review summarizes the current state of lactulose production by chemical and biological methods.

Recycling of Plant Fiber Resources: Enhanced Hydration of Newspaper Stock for Decrease of Deinking Reject (식물유래 섬유자원의 재활용: 탈묵 수율 개선을 위한 신문 지료의 수화 촉진 방안)

  • Chung, Sung-Hyun;Kim, Joong-Ho;Joo, Jong-Hun;Bang, Jae-Wook
    • Proceedings of the Korea Technical Association of the Pulp and Paper Industry Conference
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    • 2011.10a
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    • pp.39-41
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    • 2011
  • The recycling rate of recovered paper in Korea is the highest in the world, 92%, but remanufacturing yield is low due to the extremely poor quality of the paper. The poor quality, in turn, influences to the reject amount in deinking process. To increase the yield of old newspaper recycling process, hydrophobic degree of inorganic pigments of deinking stock must be reduced. To determine the hydrophobicity, Pitch Potential Deposit Tester (PDT) was newly designed and applied with respect to the SB latex property of various quality used in Korea; its hydrophobic degree according to Tg, gel content, charge and particle size of latex and optimum designing condition of SB latex. And below are the conclusions: 1. The reason of excessive reject from old newspaper deinking process for total amount of printed ink is loss of inorganic pigments. When lipase, a biochemical catalyst, was applied with the purpose of preventing inorganic pigments loss about more than 70% of total reject weight and promoting hydration of pulp for deinking, deinking process yield of pre flotation secondary stage increased remarkably without any changes of deinking efficiency. 2. Lipase improved deinking stock by cutting ester linkage on surface of hydrophobic materials to promote its hydration. From this, it reached the conclusion that hydration degree of stock exercises significant effect on flotation deinking process yield. 3. Inorganic alkali promotes hydration of deinking stock. But there have been needs for more fundamental measures other than inorganic alkali of promoting hydration for yield improvement. For this, this study intended to find out reasons of chemical properties change on surface of hydrophobic material by change of pH. 4. Pitch Deposit Test (PDT) was performed for understanding principle of why surface of coating flake from OMG is hydrophobic and why it becomes hydrophilic when pH of stock is alkaline. As a result of this test, it is determined that swelling property by change of pH of latex film, which were used as coating adhesive is the reason for hydrophobic change. 5. Hydrophilicity of coating flake increased with hydrophilic pigments. And as more of SB Latex adhesive was used and higher of calcium hardness of stock became, its hydrophilicity decreased. SB Latex adhesive film is reformed by mechanical friction. For having hydrophilicity under neutral pH, strong bruising action such as kneading is required. 6. Because swelling of adhesive film decreases as Tg of SB latex gets lower and mean diameter gets smaller, it shows hydrophobicity under neutral pH. This lowers hydrophilicity of coating flake, which leads to easy elimination with flotation reject on DIP process. Therefore, for improving future flotation yield, it is necessary to develop to use eco-friendly clean SB latex by raising Tg and increasing mean diameter for recycling, and as a result, to reduce excessive loss of coating flake as a reject from deinking process.

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Determination of the effective components in the various parts of Luffa cylindrica (L.) Roemer and development to remove the flesh from its fruit : (II) -Removal of flesh on the net fiber In fruit of sponge-gourd and improvement of quality of the net fiber- (수세미외의 부위별(部位別) 유효성분(有效成分) 조사(調査) 및 사과락중(絲瓜絡中) 육질제거(肉質除去) 방법(方法) 개발(開發) 연구(硏究) : (II) -사과락 육질제거 및 섬유품질개선-)

  • Yoo, Tae-Bang;Chang, Ki-Woon;An, Byung-Chang;Shin, Jong-Sun;Park, Joung-Sang
    • Applied Biological Chemistry
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    • v.34 no.4
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    • pp.373-378
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    • 1991
  • The skin and fleshy substance on the net fiber of sponge-gourd fruit pressed mechanically was removed with 0.2% NaOH solution in $3{\sim}5$ hours. The treatment of 0.2% NaOH with 0.02% Monopol(non-ionogenic polyoxethylen derivative) as surfactnat and with 0.1% $Ca(OCl)_2$ as bleaching agent enhanced the effect to remove the fleshy substance and improve the quality of net fiber. Also, the wet hardness and tensile strength of net fiber were controlled by the crosslinkage of the fiber with glu tardialdehyde, glyoxal, and formalin, respectively. The net fiber was stable on the acid and alkaline solutions. Also the range of temperature to degradate the fiber was $338{\sim}385^{\circ}C$. These values indicated a fair stability. The improved net fiber can be used for raw material of bath, dish washing, oil and gas filter, and many kinds of decorations.

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Effect of Annealing Temperature on the Anode Properties of TiO2 Nanotubes for Rechargeable Lithium Batteries (열처리 온도에 따른 TiO2 나노튜브의 리튬이차전지 음전극 특성)

  • Choi, Min Gyu;Kang, Kun Young;Lee, Young-Gi;Kim, Kwang Man
    • Korean Chemical Engineering Research
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    • v.50 no.1
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    • pp.25-29
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    • 2012
  • $TiO_2$ nanotubes are prepared from rutile prticles via an alkaline hydrothermal synthesis and the consequent heat treatment at $300{\sim}500^{\circ}C$. The physical and electrochemical properties of the $TiO_2$ nanotubes are characterized for use as a anode material of rechargeable lithium battery. In particular, the microscale dusts as an impurity component occurred in the purification step after the hydrothermal reaction are completely removed to yield $TiO_2$ nanotube with a higher specific surface area and more obvious crystalline phases. As the annealing temperature increases, the specific surface area is slightly decreased due to some aggregation between the isotropically dispersed nanotubes. Highest initial discharge capacity of 250 mAh $g^{-1}$ is achieved for the $TiO_2$ nanotube annealed at $300^{\circ}C$, whereas the $400^{\circ}C$ $TiO_2$ nanotube shows the superior cycle performance and high-rate capability.

Electron-microscopic studies on fine structure and enzyme activity in the axenic and conventional strains of Entamoeba histolytica (이질아메바(Entamoeba histolytica)의 미세구조 및 효소활성에 관한 전자현미경적 연구)

  • Yong, Tae-Sun;Jeong, Pyeong-Rim;Lee, Geun-Tae
    • Parasites, Hosts and Diseases
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    • v.23 no.2
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    • pp.269-284
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    • 1985
  • The metabolism of Entamoeba histolytica would be affected by various environmental factors, and alteration of the environment was known to afEect the fine structure of 5. histolytica. The present study was designed electronmicroscopically to investigate the ultrastructure and enzyme activities in the aEonic and conventional strains of 5. histolytica. The trophozoites of axenically cultivated HK-9 strain and conventional YS-27 and YS-49 strains of 5. histolytica were collected and liKed with 4% paraformaldehyde/0.1M cacodylate buffier(pH 74), After washing them by centrifugation, 1% warm agar was added in the sediment. Solidified agar with the trophozoites was cut into $lmm^3$ cubes, and incubated in the various substrates to observe enzyme activities. Then, the specimen was post-fixed with 3% glutaraldehyde/0.1M cacodylate buffer (PH 7.4) and 1% osmium tetroBide/0.1M cacodylate buffier (pH 7.4) , dehydrated in ascending ethanol series and embedded in epoxy resin. These were sectioned on an ultramicrotome and observed with a transmission electronmicroscope. The procedures for the observation of the fine structure were same as the above, except for the incubation in the substrate. The sections were stained with uranyl acetate and lead citrate. For the observation of the surface of the amoebae, scanning-electronmicroscopy was carried out. The results obtained in the present study are summarized as follows: 1. The fuzzy coat around double-layered plasma membrane of 5. histolytica was more irregularly and densely distributed in the conventional strains (YS-27, YS-49 strains) than in the axonic strain (HK-9 strain). 2. The endosomes, button bodies and chromatin material were surrounded by a double-layered nuclear membrane having scattered nuclear fores. The paranuclear body, mono- or double-layered vacuoles, vacuolar membrane whorls, rosette-like cylindrical bodies, aggregation of cylindrical bodies and helical bodies were found in the cytoplasm of the amoebae. Helical bodies and glycogen granules were generally abundant, while a few smooth endoplasmic reticula were observed in the cytoplasm. 3. Alkaline phosphatase activity was mainly demonstrated in the plasma membrane, limiting membranes of vacuoles and smooth endoplasmic reticula. ATPase activity was observed in the nucleus, limiting membranes of vacuoles and vacuolar membrane whorls. 4. Acid phosphatase activity was commonly demonstrated in the limiting membranes an contents of vacuoles, Iysosome-like organelles, plasma membrane and the button bodies in the nucleus. The activity was more weakly demonstrated in the HK-9 strain than in the other conventional strains of 5. histolytica. No peroBidase activity was observed in the amoeba strains employed in the present study. 5. With a scanning electron-microscope, no distinct structural differences were observed between the amoeba strains. All the trophozoite forms of the amoebae showed crater-like depressions and rugged features on the outer surface.

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