• Title/Summary/Keyword: Calcium peroxide

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Fabrication and Mechanical properties of Steel Fiber Reinforced Polyester Resin Composites Utilizing by-Products (Fly Ash) (산업부산물을 이용한 강섬유보강 폴리에스터 수지복합체의 제조 및 역학적 특성)

  • 박승범;윤의식
    • Proceedings of the Korea Concrete Institute Conference
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    • 1992.04a
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    • pp.35-40
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    • 1992
  • Results of an experimental study on the manufacture, the workability and mechanical properties of steel fiber reinforced polyester resin composites utilizing industrial waste products are presented in this paper. The fly ash polyester resin composites using steel fiber, fly ash and calcium carbonic acid (CaCo3), unsaturated polyester resin, styrene monomer, cobalt octate and methyl ethyl ketone peroxide, fine and coarse aggregates are prepared with various filler~binder rations, binder rates and mixing conditions. As a test results, the workability of steel fiber reinforced polyester resin composites are considerably dropped with increasing fly ash-binder ratio and steel fiber volume. And compressive, flexural strength and bending toughness of the composites are remarkably improved with augmenting fiber contents.

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Primary astrocytic mitochondrial transplantation ameliorates ischemic stroke

  • Eun-Hye Lee;Minkyung Kim;Seung Hwan Ko;Chun-Hyung Kim;Minhyung Lee;Chang-Hwan Park
    • BMB Reports
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    • v.56 no.2
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    • pp.90-95
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    • 2023
  • Mitochondria are important organelles that regulate adenosine triphosphate production, intracellular calcium buffering, cell survival, and apoptosis. They play therapeutic roles in injured cells via transcellular transfer through extracellular vesicles, gap junctions, and tunneling nanotubes. Astrocytes can secrete numerous factors known to promote neuronal survival, synaptic formation, and plasticity. Recent studies have demonstrated that astrocytes can transfer mitochondria to damaged neurons to enhance their viability and recovery. In this study, we observed that treatment with mitochondria isolated from rat primary astrocytes enhanced cell viability and ameliorated hydrogen peroxide-damaged neurons. Interestingly, isolated astrocytic mitochondria increased the number of cells under damaged neuronal conditions, but not under normal conditions, although the mitochondrial transfer efficiency did not differ between the two conditions. This effect was also observed after transplanting astrocytic mitochondria in a rat middle cerebral artery occlusion model. These findings suggest that mitochondria transfer therapy can be used to treat acute ischemic stroke and other diseases.

Amperometric Determination of Histamine using Immobilized Enzyme Reactors with Different Carriers (담체 고정화 효소 반응기를 이용한 Histamine의 전기화학적 측정)

  • Ji, Jung-Youn;Jeon, Yeon-Hee;Kim, Mee-Ra
    • Journal of the East Asian Society of Dietary Life
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    • v.22 no.1
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    • pp.88-94
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    • 2012
  • Histamine is a kind of primary biogenic amine arising from the decarboxylation of the amino acid L-histidine. The toxicology of histamine and its occurrence and formation in foods are especially emphasized in fermented foods. In this study, the biosensor for detection of histamine with functionalized multi-walled carbon nanotubes (MWCNT) was developed. We also searched for an appropriate insoluble substrate to immobilize the enzyme. The developed biosensor showed a detection limit of $0.1{\mu}M$ hydrogen peroxide. The enzyme reactor was prepared with diamine oxidase immobilized on insoluble carriers including CNBr-activated sepharose 4B, calcium alginate, and controlled pore size glass beads. The coupling efficiency of CNBr-activated sepharose 4B, calcium alginate, and controlled pore size glass beads were 48.5%, 40.3%, and 51.0%, respectively. In addition, the response currents on histamine with each immobilized enzyme reactor prepared with CNBr-activated sepharose 4B, calcium alginate, and controlled pore size glass beads were 120 nA, 110 nA, and 140 nA at $100{\mu}M$ of histamine concentration, respectively. Therefore, it is suggested that controlled pore size glass beads are the best carriers for immobilizing diamine oxidase to detect histamine in this biosensor.

Effect of acidic electrolyzed water on the quality improvement of boiled-dried anchovy (자건 멸치의 품질 개선에 대한 산성 전해수의 영향)

  • Lee, Soo-Jung;Sung, Nak-Ju;Kang, Shin-Kwon
    • Food Science and Preservation
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    • v.21 no.3
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    • pp.357-364
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    • 2014
  • The quality improvement of the boiled-dried anchovy treated with acidic electrolyzed water (AEW) was investigated. The L value was higher in the anchovy treated with AEW than in the control. Moreover, its ${\Delta}E$ value was 5.08 higher than that of the control. The lipophilic browning degree was also higher than the hydrophilic degree. The degrees of calcium absorption of the control and anchovy treated with AEW were 10.77% and 12.61%, respectively. During their storage in the different conditions (five weeks in $20^{\circ}C$, ten weeks in $4^{\circ}C$, and five months in $-20^{\circ}C$), the lipophilic browning degree of the anchovy treated with AEW was significantly lower than that of the control at the $20^{\circ}C$ storage. The volatile basic nitrogen (VBN) content gradually increased as the storage period increased. During the $20^{\circ}C$ storage, the content of the anchovy treated with AEW was lower than that of the control. The lipid peroxide contents increased with the storage periods, regardless of the temperature, but the content of the anchovy treated with AEW was lower than that of the control. These results indicate that AEW treatment can improve the color quality of boiled-dried anchovy and reduce its VBN and lipid peroxide contents.

A Study on Storage Stability and Calcium Contents Extracted from anchovy According to Particle Sizes (멸치의 분말 크기에 따른 저장 안정성과 칼슘 용출량에 관한 연구)

  • 이수경
    • Journal of Food Hygiene and Safety
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    • v.13 no.3
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    • pp.196-200
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    • 1998
  • The relationship between storage stability and calcium contents extracted from anchovy according to particle sizes was investigated in this paper. The results are as follows; 1. The acid value (A Y) and the peroxide value (POY) of anchovy were in the rank order of whole anchovy<35<50<80 mesh by particle sizes and 6<12<18<30 months by storage term. 2. The Calcium (Ca) and Phosphorus (P) contents extracted from anchovy were in the rank order of whole anchovy<35<50<80 mesh by particle sizes and 10<20<30 minutes by heating time. The extracted amount of Ca was the largest when anchovy particles with 80 mesh were heated for 30 minutes. In that case the amount of Ca in the anchovy stocks was 52.54 mg. 3. The amount ratio between Ca and P was in the rank order of 30<20<10 minutes by boiling time and indicated 1:3.99~5.16 by each part. The lowest ratio of Ca to P was 1:3.99 when anchovy particles with 80 mesh were heated for 30 minutes.

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Preparation and Characteristics of Snack Using Conger Eel Frame (붕장어 Frame을 이용한 스낵의 제조 및 특성)

  • Kim, Hye-Suk;Kang, Kyung-Tae;Han, Byung-Wook;Kim, Eun-Jung;Heu, Min-Soo;Kim, Jin-Soo
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.10
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    • pp.1467-1474
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    • 2006
  • Fish-frames, which are left after obtaining fillets or muscle during fish processing, consists of useful food components, such as muscle, collagen, calcium, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). This study was carried out to prepare snack using conger eel frame (SF) for human consumption and also to elucidate food component characterization of the snack. The results of volatile basic nitrogen suggested that conger eel frame was a suitable material for preparing snack. Based on the results of sensory evaluation and costs, starch syrup was an optimal sweetener for preparing snack using conger eel frame. The starch syrup-treated SF appeared safe because the moisture content and peroxide value were below the safety limits described in the guideline of Korea Food and Drug Administration (KFDA). Starch syrup-treated SF was similar in the pattern of fatty acid composition to soybean oil, whereas EPA and DHA were detected in SF. The total content of amino acid in starch syrup-treated SF was 23.9% based on 100 g of raw material. The maj or amino acids were aspartic acid, glutamic acid, glycine and alanine. The total contents of calcium and phosphorus in starch syrup-treated SF were 4.9% and 2.8%, respectively. The Ca/P of starch syrup-treated SF was 1.9, which is a good ratio for absorption of calcium. The SF made with starch syrup was superior in EPA and DHA compositions, total amino acid, calcium and phosphorus contents to commercial snack using eel frame.

The effect of fluoride and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) pplication on the color and microhardness of bleached enamel (치아미백 후 불소와 CPP-ACP 처리가 치아의 색과 미세경도에 미치는 영향)

  • Shim, Youn-Soo;Choi, Woo-Yang
    • Journal of Korean society of Dental Hygiene
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    • v.10 no.3
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    • pp.473-481
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    • 2010
  • Objectives : To evaluate the effect of fluoride application on the color and microhardness of bleached enamel and compare it to that of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) application. Methods : Twenty freshly extracted human adult molar were each sectioned into halves, the specimens divided and treated according to five experimental groups: Group 1, treatment with 10% carbamide peroxide (CP) bleaching agent; Group 2, treatment with 10% CP followed by a 1.23% fluoride gel application; Group 3, treatment with 10% CP followed by a 2.23% sodium fluoride varnish application; Group 4, treatment with 10% CP followed by a 0.11% sodium fluoride gel application; Group 5, treatment with 10% CP followed by a CPP-ACP gel application. All groups were treated 6 h per day for 14 days then immersed in distilled water for 2 weeks. Changes in enamel color were evaluated on Baseline and Day 14. Microhardness were evaluated on Baseline, Days 7 and 14. Statistical analysis was performed using one-way ANOVA and post-hoc Tukey tests. Results : All the bleached enamel specimens revealed increased whiteness and overall color value. Group 1 showed the lowest microhardness values than that of Groups 2, 3, 4 and 5. In all groups, the hardness of tooth after bleaching showed a significant decrease in the microhardness as compared with the one prior to tooth bleaching. The specimens treated with remineralizing agents showed relatively less reduction in enamel microhardness than control group. Conclusions : The addition of fluoride and CPP-ACP did not impede the whitening effect. The use of remineralizing agents during bleaching treatment can significantly enhance the microhardness of bleached enamel.

Effects of Chrysanthemum indicum L. Extract on the Function of Osteoblastic MC3T3-E1 Cells under Oxidative Stress Induced by Hydrogen PeroxideJee (감국(Chrysanthemum indicum L.) 추출물이 H2O2로 유도한 산화적 스트레스에서 MC3T3-E1 조골세포 기능에 미치는 영향)

  • Yun, Jee-Hye;Hwang, Eun-Sun;Kim, Gun-Hee
    • Korean Journal of Food Science and Technology
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    • v.44 no.1
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    • pp.82-88
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    • 2012
  • Chrysanthemum indicum L. (Asteraceae) is a traditional herbal medicine that has been used for the treatment of inflammation, hypertension, and respiratory diseases due to its strong antagonistic activity against inflammatory cytokines. The effects of Chrysanthemum indicum L. Extract (CIE) for increasing cell growth, alkaline phosphatase (ALP) activity, and collagen content were totally inhibited, suggesting that the effect of CIE might be partly involved with estrogen activity. Furthermore, the protective effects of CIE on the response of osteoblasts to oxidative stress were evaluated. Osteoblastic MC3T3-E1 cells were incubated with hydrogen peroxide and/or CIE, and markers of osteoblast function and oxidative damage were examined. CIE significantly increased cell survival, ALP activity, and calcium deposition, and decreased the production of Reactive Oxygen Species (ROS) and Tumor Necrosis Factor-${\alpha}$ (TNF-${\alpha}$) in osteoblasts. Taken together, these results indicate that the enhancement of osteoblast function by CIE may prevent osteoporosis and inflammatory bone diseases.

Aluminum Stress Inhibits Root Growth and Alters Physiological and Antioxidant Enzyme Responses in Alfalfa (Medicago sativa L.) Roots (알팔파 뿌리에 있어서 알루미늄 스트레스 처리에 따른 뿌리 생장 저해와 생리 및 항산화 반응의 변화)

  • Min, Chang-Woo;Khan, Inam;Lee, Byung-Hyun
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.39 no.4
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    • pp.298-302
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    • 2019
  • Acidic soil significantly reduces crop productivity mainly due to aluminum (Al) toxicity. Alfalfa (Medicago sativa L.) roots were exposed to aluminum stress (Al3+) in calcium chloride (CaCl2) solution (pH4.5) and root growth, physiological and antioxidant enzyme responses were investigated. The root growth (length) was significantly inhibited after 48 h of aluminum stress imposition. Histochemical staining with hematoxylin indicated significant accumulation of aluminum in Al stress-treated root tissues. Histochemical assay were also performed to detect superoxide anion, hydrogen peroxide and lipid peroxidation, which were found to be more in root tissues treated with higher aluminum concentrations. The enzymatic activity of CAT, POD and GR in root tissues was slightly increased after Al stress treatment. The result suggests that Al stress alters root growth in alfalfa and induces reactive oxygen species (ROS) production, and demonstrates that antioxidant enzymes involved in detoxification of Al-mediated oxidative stress.

A Study on Bloating of Porous Foam by Pressure Infiltration with H2O2 (과산화수소의 가압침투에 의한 다공성 발포체에 관한 연구)

  • Kim, Gui-Shik;Jeong, Ji-Hyun
    • Journal of Power System Engineering
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    • v.20 no.5
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    • pp.86-91
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    • 2016
  • This paper is concerned chiefly with the method of porous foam manufacture using basalt stone powder sludge. The hydrogen peroxide($H_2O_2$) of bloating agent has lots of problems to manufacture porous lightweight aggregate due to fast reaction rate with cement or calcium hydroxide($Ca(OH)_2$). The $H_2O_2$ injecting method using nozzle for manufacturing porous lightweight aggregate is proposed, in this study. This method is to inject $H_2O_2$ at the pressure of 10 MPa on upper side of slurry mixing materials such as stone powder sludge and quick-lime(CaO) by injector. The specimen was dried in furnace at $100^{\circ}C$ for 1 hour and cured at ambient temperature for 30 days. We analyzed the characteristics including specific gravity and water absorption. The experiments were found that the porous foam has low specific gravity, high water absorption and uniform distribution of porous more than manufactured foam by general bloating methods.