• Title/Summary/Keyword: Ca addition

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A Study on the Early Hydration-Retarding Mechanism of Polymer Modified Cement (Polymer Modified Cement의 초기 수화 지연 mechanism에 관한연구)

  • Kang, Seung-Min;Kang, Hyun-Ju;Song, Myong-Shin;Park, Phil-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2009.05a
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    • pp.221-222
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    • 2009
  • The results showed that the addition of VAE polymer strongly reduces the $Ca(OH)_2$ formation, being this result attributed to reduce degree of cement hydration caused by different ion elution amount of polymer modified cement pastes and interaction between acetate anion from the partial hydrolysis of co-polymer and Ca$^{2+}$ion from OPC hydration.

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Role of NADPH Oxidase-Mediated Generation of Reactive Oxygen Species in the Mechanism of Apoptosis Induced by Phenolic Acids in HePG2 Human Hepatoma Cells

  • Lee, Yong-Soo
    • Archives of Pharmacal Research
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    • v.28 no.10
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    • pp.1183-1189
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    • 2005
  • Although plant-derived phenolic acids have been reported to have anti-cancer activity, the exact mechanism is not completely understood. In this study, we investigated the role for reactive oxygen species (ROS) as a mediator of the apoptosis induced by caffeic acid (CA) and ferulic acid (FA), common phenolic acids in plants in HepG2 human hepatoma cells. CA and FA reduced cell viability, and induced apoptotic cell death in a dose-dependent manner. In addition, they evoked a dose-related elevation of intracellular ROS. Treatment with various inhibitors of NADPH oxidase (diphenylene iodonium, apocynin, neopterine) significantly blunted both the generation of ROS and the induction of apoptosis induced CA and FA. These results suggest that ROS generated through activation of NADPH oxidase may play an essential role in the apoptosis induced by CA and FA in HepG2 cells. These results further suggest that CA and FA may be valuable for the therapeutic management of human hepatomas.

Effect of MgO on Microstructural Evolution of Alumina Prepared from Hydrosol-Gel Process of Boehmite in Plaster Mold (석고몰드속에서 Boehmite의 Hydrosol-Gel로부터 제조된 알루미나의 미세구조에 미치는 M\ulcorner의 영향)

  • 오경영;정창주
    • Journal of the Korean Ceramic Society
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    • v.30 no.12
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    • pp.1029-1038
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    • 1993
  • The microstructures of aluminas, included of dissolved CaO as $\alpha$-alumina seeded pseudo-boehmite hydrosol was gelled in plaster mold and doped of MgO as dipping of calcines(120$0^{\circ}C$-2h) into Mg-nitrate solution, were compared to the one of which additives are excluded during the gellation. It was formed the boundary layer of 300~350${\mu}{\textrm}{m}$ distance from surface to the inside, containing of approximately 500ppm CaO by dissolved Ca from plaster mold. As the MgO addition to the boundary layer with dissolved CaO, the microstructure of the layer was uniformed and inhibited the grian growth, compared to one of that additives be excluded specimen and of MgO doped-inside region. This result was considered as abnormal grain growth and effect of flat boundary formation be appeared by effects of dissolved CaO, were decreased by MgO co-doping.

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Fault Diagnosis in the CA Analyzer and Fault Detection of the Input Sequence (CA 분석기의 오류진단과 오류가 있는 입력수열의 오류탐지)

  • Cho, Sung-Jin;Kwon, Min-Jeong;Yim, Ji-Mi;Kim, Jin-Gyoung;Park, Young-Gyu
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.13 no.10
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    • pp.2129-2139
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    • 2009
  • In this paper, we diagnose the fault in the CA analyzer by setting up the initial value such that the final test signature is a constant regardless of the circuit being tested. This method makes the CA test procedure short and clear. In addition, we detect the fault of the faulty input sequence by using the inverse matrix of the CA state transition matrix.

Genetic Polymorphism of MTHFR A1298C and Esophageal Cancer Susceptibility: A Meta-analysis

  • Tan, Xiang;Wang, Yong-Yong;Dai, Lei;Liao, Xu-Qiang;Chen, Ming-Wu
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.1951-1955
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    • 2013
  • Background: Associations between the methylenetetrahydrofolate reductase (MTHFR) A1298C polymorphism and esophageal cancer risk have been reported in many articles recently, but results were controversial. Therefore the present meta-analysis was conducted to to provide a more precise estimation. Methods: Odds ratios (ORs) with 95% confidence intervals (CIs) were used to evaluate the strength of associations. Results: Finally, six case-control studies involving a total of 1,302 cases and 2,391controls for the A1298C polymorphism were included. The meta-analysis showed that significantly increased risk for Asians (CC versus AA, OR=3.799, 95%CI=1.541-9.365, P=0.004; CCversusCA+AA, OR=3.997, 95%CI=1.614-9.900, P=0.003) and Caucasians (CC versus AA, OR=1.797, 95%CI=1.335-2.418, P=0.000; CC+CA versus AA,OR=1.240, 95%CI=1.031-1.492, P=0.022; CCversusCA+AA, OR=1.693, 95%CI=1.280-2.240, P=0.000). In addition, there was an association with risk for both ESCC (CC versus AA, OR=2.529, 95%CI=1.688-3.788, P=0.000; CCversusCA+AA, OR=2.572, 95%CI=1.761-3.758, P=0.000) and esophageal adenocarcinoma (EAC) (CC versus AA, OR=1.592, 95%CI=1.139-2.227, P=0.007; CC+CA versus AA,OR=1.247, 95%CI=1.016-1.530, P=0.035; CCversusCA+AA, OR=1.466, 95%CI=1.069-2.011, P=0.018). Conclusion: This meta-analysis suggested associations of the A1298C polymorphism with increased risk of esophageal cancer in both Asians and Caucasians. In addition, we found that the MTHFR A1298C polymorphism might influence risk ofESCC and EAC in the overall studies.

Effects of $Ca^{2+}$ and $HCO_3{^-}$ on Capacitation, Hyperactivation and Protein Tyrosine Phosphorylation in Guinea Pig Spermatozoa

  • Huang, Jing-yan;Wang, Gen-lin;Kong, Li-juan
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.2
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    • pp.181-186
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    • 2009
  • In our previous report, we demonstrated that the tyrosine phosphorylation of sperm proteins (TPSP) of guinea pig was associated with capacitation and hyperactivation (CAHA), and $Ca^{2+}$ and ${HCO_3}^-$ were required for the initiation of CAHA and increasing the TPSP. The aim of this study was to further investigate the mechanism underlying the above events. The results showed that addition of cAMP agonists, dibutyryl-cAMP (db-cAMP) and isobutyl-methylxantine (IBMX), to ${HCO_3}^-$ -free medium significantly increased CAHA to the normal level (when sperm were incubated in TALP). Although addition of the cAMP agonists to $Ca^{2+}$-free medium increased CAHA, the percentages of hyperactivated and capacitated sperm were still significantly lower than the normal level. Compared with ${HCO_3}^-$ -free or $Ca^{2+}$-free medium, TPSP was increased when db-cAMP and IBMX were added in the media. H-89, a specific inhibitor of protein kinase A (PKA), inhibited CAHA in a dose-dependent manner and totally blocked TPSP. These results confirm a previous observation that $Ca^{2+}$ and ${HCO_3}^-$ regulated CAHA and TPSP in a cAMP/PKA pathway, and support an interation between TPSP and CAHA of sperm. Besides the cAMP/PKA pathway, $Ca^{2+}$ might have also played a role in regulating CAHA by other pathways since the normal level of CAHA did not recover by adding cAMP agonists in the media.

Combined Treatment on the Inactivation of Naturally Existing Bacteria and Escherichia coli O157:H7 Inoculated on Fresh-Cut Kale

  • Kang, Ji Hoon;Song, Kyung Bin
    • Journal of Microbiology and Biotechnology
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    • v.27 no.2
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    • pp.219-225
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    • 2017
  • An aqueous chlorine dioxide ($ClO_2$) treatment combined with highly activated calcium oxide (CaO) and mild heat was tested for inactivating naturally existing bacteria and Escherichia coli O157:H7 inoculated on fresh-cut kale. Kale samples were treated with different concentrations of $ClO_2$ (10, 30, and 50 ppm), CaO (0.01%, 0.05%, 0.1%, and 0.2%), and mild heat ($25^{\circ}C$, $45^{\circ}C$, $55^{\circ}C$, and $65^{\circ}C$) as well with combinations of 30 or 50 ppm $ClO_2$ and 0.2% CaO at $55^{\circ}C$ for 3 min. An increasing concentration of $ClO_2$ and CaO significantly reduced the microbial population compared with the control. In addition, mild heating at $55^{\circ}C$ elicited greater microbial reduction than the other temperatures. A combined treatment of 50 ppm $ClO_2$ and 0.2% CaO at $55^{\circ}C$ reduced the population of naturally existing bacteria on kale by 3.10 log colony forming units (CFU)/g, and the counts of E. coli O157:H7 were below the detection limit (1 log CFU/g). In addition, no significant differences in the Hunter color values were evident in any treatment during storage. Therefore, a combined treatment of $ClO_2$ and active CaO at $55^{\circ}C$ can be an effective sanitizing method to improve the microbiological safety of fresh-cut kale without affecting its quality.

Change of Fermentation Characteristic of Kimchi by n-Capric Acid or n-Capric Acid Methyl Ester Addition and Storage Temperature (n-Capric Acid 또는 n-Capric Acid Methyl Ester 첨가와 저장온도에 따른 김치의 발효특성)

  • Kim, Byung-Yong;Ahn, Tae-Young;Kim, Myung-Hwan
    • Applied Biological Chemistry
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    • v.42 no.2
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    • pp.156-161
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    • 1999
  • This study was conducted to investigate the effects of n-capric acid(CA) or n-capric acid methyl ester (CE) addition during salting process, and fermentation temperature on chemical and microbial changes of Kimchi. The pHs of control, CA and CE were 3.78, 4.28 and 4.35 after 6 days of storage at $20^{\circ}C$ and were 3.85, 5.14 and 5.10 after 42 days of storage at $4^{\circ}C$, respectively. The effects of CA or CE addition at $4^{\circ}C$ were higher than those at $20^{\circ}C$. The maximum edible acidity, 0.75%, was reached within 3 days at $20^{\circ}C$, 15 days at $12^{\circ}C$, and the acidity of 42 days at $4^{\circ}C$ was 0.62% which was still lower value than the maximum edible acidity. Total bacteria, Leuconostoc, Lactobacillus and yeast counts of the control were higher value than those of the treatments throught the whole fermentation period. The addition of CE at $4^{\circ}C$ had much affected the reduction of yeast count. As microbial counts and reduction rates of control and treated Kimchi increased with increasing the storage temperature.

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Effect of Glycyrrhizae Radix on the Immune Responses(II) - Immuno-regulatory Action of Glycyrrhizin and Glycyrrhetinic Acid - (감초가 면역반응에 미치는 영향(II) - Glycyrrhizin 및 Glycyrrhetinic acid의 면역조절작용 -)

  • 한종현;오찬호;은재순
    • YAKHAK HOEJI
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    • v.35 no.3
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    • pp.174-181
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    • 1991
  • These experiments were conducted to investigate the effects of glycyrrhizin(GL) and glycyrrhetinic acid(GA) on histamine synthesis, lymphocyte blastogenesis in C57BL/6J mice splenocytes, IL-1 production, $Ca^{2+}$ uptake by macrophage-like P388D$_{1}$ cells and plaque forming cell assay against SRBC. Histamine contents, lymphocyte blastogenesis, IL-1 activity, $Ca^{2+}$ uptake and plaque forming cell were determined by enzyme isotope method, [sup 3/H]-thymidine incorporation, C3H/HeJ mouse thymocytes proliferation, the addition of 5 $\mu$Ci/ml $^{45}$Ca$^{2+}$ to P388D$_{1}$, cell suspension and assay to sheep red blood cell, respectively. Cytotoxicity, which was expressed as 50% mortality, was occurred by the addition of GL(10$^{-3}$M) and GA(10$^{-4}$M). Histamine production in mouse spleen cell culture was significantly increased by the addition of 0.25 $\mu\textrm{g}$/ml of Con A, after 48 hour incubation. Con A dependent T-lymphocyte proliferation was also enhanced by the addition of 0.25 .mu.g/ml of Con A. The effects of GL on histamine contents and T-lymphocyte proliferation were significantly decreased at high dose (10$^{-5}$M), while IL-1 activity was remarkably suppressed by 10$^{-8}$~10$^{-4}$M of GL. $Ca^{2+}$ uptake was not changed, but antibody production was increased by GL(10 mg/kg). GA inhibited histamine contents at 10$^{-9}$~10$^{-7}$ and depressed Con A (0.25 $\mu\textrm{g}$/ml) dependent T-lymphocyte proliferation at 10$^{-7}$~10$^{-5}$M of GA, but increased suboptimal dose (Con A 0.1 $\mu\textrm{g}$/ml) at 10$^{-9}$~10$^{-7}$M of GA. IL-1 activity was suppressed by 10$^{-8}$~10$^{-4}$M of GA and $Ca^{2+}$ uptake was enhanced by 10$^{-9}$~10$^{-6}$ of GA, but antibody production was not changed by GA. From the above results, it is suggested that GL and GA have immuno-regulatory action. GL decreased cell-mediated immune response, and increased humoral immune response at high dose. On the other hand, low dose of GA enhanced cell-mediated immune response, while high doses of GA decreased humoral immune reaction.

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Formation and Structure of $CaO-P_2O_5-SiO_2$ Glasses ($CaO-P_2O_5-SiO_2$계 유리의 형성 및 구조)

  • 조정식;김철영
    • Journal of the Korean Ceramic Society
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    • v.29 no.9
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    • pp.729-738
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    • 1992
  • The glass formation and structural change with the glass compositions were investigated in the CaO-P2O5-SiO2 system with less than 40 wt% of P2O5. The glass formation range was determined by XRD, SEM and EDS techniques for water quenched specimens. The structural analyses were made for binary CaO-SiO2 glasses and ternary CaO-P2O5-SiO2 glasses by using FT-IR and Raman spectroscopy. The glass formation was affected by CaO/SiO2 mole ratio, P2O5 content and primary crystalline phase. The stable glass formation range was found when the transformed CaO/SiO2 mole ratio (new factor derived from structural changes) was in the range of 0.72~1.15 with less than 10 mol% of P2O5. The structural analyses of CaO-SiO2 glasses indicated that as the CaO/SiO2 ratio was increased, the nonbridging oxygens in the structural unit of the glasses were increased. With addition of P2O5 to CaO-SiO2 glasses, the P2O5 enhanced the polymerization of [SiO4] tetrahedra unit in CaO-SiO2 glasses, which contained a large portion of nonbridging oxygen. The phosphate eliminated nonbridging oxygens from silicate species, forcing polymerization of silicate structures and produced in [PO4] monomer in glasses. When added P2O5 was kept constant, the structural change with various CaO/SiO2 ratio was very similar to that of CaO-SiO2 glasses.

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