• Proceedings of the KACD Conference
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• 2001.11a
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• pp.552-552
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• 2001

Bacterial lipopolysaccharide (LPS) plays a major role in the development of periapical bone resorption. IL-1 and $TNF-{\alpha}$ are known to stimulate bone resorption and inhibit bone formation. Recent evidence has indicated that polymorphonuclear leukocytes (PMNs) have the ability to release IL-1 and $TNF-{\alpha}$ Calcium hydroxide is an effective medicament in root canal infections, reducing the microbial titre within the canal. It has been proposed that the therapeutic effect of $Ca(OH)_2$ may also be the result of direct inactivation of LPS.(omitted)

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.562.1-562
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• 2001

Bacterial lipopolysaccharide (LPS) plays a major role in the development of periapical bone resorption. IL-1 and $TNF-{\alpha}$ are known to stimulate bone resorption and inhibit bone formation. Recent evidence has indicated that polymophonuclear leukocytes(PMNs) have the ability to release IL-1 and $TNF-{\alpha}$ Calcium hydroxide is an effective medicament in root canal infections, reducing the microbial titre within the canal. It has been proposed that the therapeutic effect of $CA(OH)_2$ may also be the result of direct inactivation of LPS.(omitted)

• Journal of Surface Science and Engineering
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• v.54 no.5
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• pp.238-247
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• 2021

PEO (plasma electrolytic oxidation) was applied to modify the surface of AZ31 magnesium alloy in this study. The mixed solution of sodium hydroxide (NaOH) and sodium silicate (Na₂SiO₃) was used as the electrolyte, and 0 - 0.05 g/L of Ca-GP (Glycerol Phosphate Calcium salt) was added in the electrolyte as an additive. PEO treatment was conducted at a current density of 30mA/cm² for 5 minutes using a DC power supply. The surface properties were identified by SEM, XRD and surface roughness analyses, and the corrosion resistance was evaluated by potentiodynamic polarization and immersion tests. In addition, the biocompatibility was evaluated by immersion test in SBF solution. As the concentration of Ca-GP was increased, the surface morphology was denser and more uniform, and the amount of Ca and the thickness of oxide layer increased. Only Mg peak was observed in XRD analysis due to very thin oxide layer. The corrosion resistance of PEO-treated samples increased with the concentration of Ca-GP in comparision with the untreated sample. In particular, the highest corrosion resistance was identified at the group of 0.04g Ca-GP through potentiodynamic polarization and immersion tests in saline solution (0.9 wt.%NaCl). During the immersion in saline solution, pH rapidly increased at the beginning of immersion period due to rapid corrosion, and then increase rate of pH decreased. However, the pH value in the SBF temporarily increased from 7.4 to 8.5 during the day, then decreased due to the inhibition of corrosion with HA(hydroxyapatite) formation.

• Restorative Dentistry and Endodontics
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• v.34 no.2
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• pp.120-129
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• 2009

The purpose of this study was to investigate the pulpal response to direct pulp capping with dentin sialoprotein (DSP) -derived synthetic peptide in teeth of dogs, and to compare its efficacy to capping substances $Ca(OH)_2$ and white mineral trioxide aggregate (WMTA). A total of 72 teeth of 6 healthy male beagle dogs were used. The mechanically exposed pulps were capped with one of the following: (1) DSP-derived synthetic peptide (PEP group): (2) $Ca(OH)_2$ (CH group): (3) a mixture paste of peptide and $Ca(OH)_2$ (PEP+CH group): or (4) white MTA (WMTA group). The access cavity was restored with a reinforced glass ionomer cement. Two dogs were sacrificed at each pre-determined intervals (2 weeks, 1 month, and 3 months). After the specimens were prepared for standard histological processing, sections were stained with hematoxylin and eosin. Under a light microscope, inflammatory response and hard tissue formation were evaluated in a blind manner by 2 observers. In the PEP group, only 3 of 17 specimens showed hard tissue formation, indication that the DSP-derived synthetic peptide did not induce proper healing of the pulp. Compared with the CH group, the PEP group demonstrated an increased inflammatory response and poor hard tissue formation. The CH and WMTA groups showed similar results for direct pulp capping in mechanically exposed teeth of dogs.

• Journal of the Mineralogical Society of Korea
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• v.27 no.4
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• pp.207-222
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• 2014

In order to recover the metallic copper powder from the mine-waste rock, heap bioleaching, Fe removal and electrowinning experiments were carried out. The results of heap leaching with the mine-waste rock sample containing 0.034% Cu showed that, the leaching rate of Cu were 61% and 62% in the bacteria leaching and sulfuric acid leaching solution, respectively. Sodium hydroxide (NaOH), hydrogen peroxide ($H_2O_2$) and calcium hydroxide ($Ca(OH)_2$) were applied to effectively remov Fe from the heap leaching solution, and then $H_2O_2$ was selected for the most effective removing Fe agent. In order to prepare the electrolytic solution, $H_2O_2$ were again treated in the heap leaching, and Fe removal rates were 99% and 60%, whereas Cu removal rates were 5% and 7% in the bacteria and sulfuric acid leaching solutions, respectively. After electrowinning was examined in these leaching solution, the recovery rates of Cu were obtained 98% in bacteria and obtained 76% in the sulfuric leaching solution. The dendritic form of metallic copper powder was recovered in both leaching solutions.

• Journal of the Korean Recycled Construction Resources Institute
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• v.6 no.3
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• pp.110-117
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• 2011

This study investigated possibilities for a new reducing shrinkage method of soybean oil(SO) and waste oil(WO) to compare with shrinkage reducing agent(RS) and expansion additive(EA). There was no big difference to flow, air contents, and compressive strength of plain to use SO and WO. For the reducing shrinkage performance, SO and WO was more effective than RS and EA, because their fatty acid reacted with calcium hydroxide of concrete to turn soap. For the pore distribution by porosimter, $0.01{\sim}0.1{\mu}m$ pores of SO and WO were 0 ml/g, and $10{\sim}100{\mu}m$ also remarkably lower than any others. In these results, it inferred that they filled up capillary pore and mitigated autogenous shrinkage by their saponification of their fatty acid and calcium hydroxide.

• Restorative Dentistry and Endodontics
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• v.29 no.5
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• pp.470-478
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• 2004

The purpose of this study is to monitor the secretion of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) produced by human osteosarcoma cell line (MG63) stimulated with Prevotella nigrescens lipopolysaccharides (LPS). and to compare the level of secretion before and after the treatment of calcium hydroxide on P. nigrescens LPS. LPS was extracted and purified from anaerobically cultured P. nigrescens. MG63 cells were stimulated by the LPS (0, 1, $10{\;}\mu\textrm{g}/ml$) or LPS($10{\;}\mu\textrm{g}/ml$) pretreated with 12.5 mg/ml of $Ca(OH)_2$ for 3 days. Total RNA was isolated from the cell. and real-time quantitative polymerase chain reaction (PCR) was performed for quantification of MMP-1 and TIMP-1. The results were as follows. 1. MMP-1 mRNA expression at 48 hr was highly increased by stimulation with P. nigrescens LPS. The increase was dose-dependent. 2. When stimulated with ($1{\;}\mu\textrm{g}/ml$ of LPS. TIMP-1 mRNA expression was highly increased at 24 hr and 48 hr. However. TIMP-1 expression was suppressed at higher concentration ($10{\;}\mu\textrm{g}/ml$). 3. When P. nigrescens LPS was pretreated with $Ca(OH)_2$. MMP-1 and TIMP-1 gene expression was downregulated. The results of this study suggest that transcriptional regulation of MMP-1 and TIMP-1 by P. nigrescens LPS could be one of the important mechanisms in bone resorption of periapical inflammation. The result of calcium hydroxide on MMP-1 and TIMP-1 gene expression suppression shows that calcium hydroxide detoxified bacterial LPS and thus should be used the medication of choice for intracanal dressings in root canal infected with black-pigmented bacteria.

• Journal of the Korea Institute of Building Construction
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• v.15 no.6
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• pp.553-559
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• 2015

In this study, to suggest the application method of recycled fine aggregate, the non-cement mortar was prepared and studied with the binders of blast furnace slag, fly ash, and fly ash from combined heat power plant. As a basic experiment, a series of tests was conducted to determine the potions of the binders and types of activator. When the binder was consisted with 20% of fly ash and 40% of fly ash from combined heat power plant, the highest strength of the mortar was obtained, and as an activator, the combination of sodium hydroxide 2.5%, and calcium hydroxide 7.5% showed the highest strength of the mortar. Therefore, this study focuses on engineering properties of mortar contains fly ash from combined heat power plant and recycled fine aggregate according to replacement ratio of recycled fine aggregate based on the optimum mix from the basic experiment. As a result, the best replacement ratio of recycled fine aggregate is 75%.

• Asian-Australasian Journal of Animal Sciences
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• v.15 no.1
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• pp.26-33
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• 2002

In order to assess the effect of feeding raw or processed cotton (Gossypium) seed meal (CSM) on meat and wool production, 30 male crossbred lambs (3-4 months) of uniform body weight were assigned equally to five dietary treatments in a completely randomised design. The CSM was processed by three different methods i.e., cooking the meal at $100^{\circ}C$ for 45 minutes, treatment with 1% calcium hydroxide ($Ca(OH)_2$) for 24 h and iron treatment in the ratio of 1 part free gossypol (FG) to 0.3 parts of iron for 30 minutes. The lambs were fed isonitrogenous and isocaloric concentrate mixtures, containing 30% deoiled peanut meal (reference diet) and 40% of either raw, cooked, $Ca(OH)_2$ or iron treated CSM for 180 days. The raw and variously processed CSM replaced about 50% nitrogen of reference concentrate mixture. The concentrate mixtures were fed to meet 80% of the protein requirements (NRC, 1985) along with ad libitum chopped maize (Zea mays) hay. The slaughter weight, empty body weight and carcass weight was higher ($p{\leq}0.01$) in lambs fed cooked CSM incorporated diets, compared to diets containing deoiled peanut meal (DPNM). These parameters were not influenced by feeding diets containing either raw, $Ca(OH)_2$ or iron treated CSM in comparison DPNM diets. The carcass length, loin eye area and edible and inedible portion of carcass and the meat: bone ratio in whole carcass were also not affected by feeding CSM based diets. Among various primal cuts, the yield of legs was lower ($p{\leq}0.05$) from raw CSM fed lambs in comparison to DPNM fed lambs. The fat content in the Longissimus dorsi muscle was reduced ($p{\leq}0.05$) in lambs fed processed CSM based diets compared to those fed DPNM diet. Replacing DPNM with either raw or processed CSM based diets did not influence the sensory attributes and overall acceptability of meat. The wool yield was higher ($p{\leq}0.05$) in iron treated CSM fed lambs. The fibre length and fibre diameter were comparable among lambs on various dietary regimes. Among lambs fed variously processed CSM diets, the feed cost per kg of edible meat production was lower ($p{\leq}0.05$) on $Ca(OH)_2$ treated CSM, followed by cooked CSM diet and then on raw CSM based diets compared to DPNM diet. The CSM after 1% $Ca(OH)_2$ treatment or cooking for 45 minutes appears to be a satisfactory protein supplement in lamb diets for meat and wool production to replace at least 50% nitrogen of scarce and costly peanut meal.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.1
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• pp.141-147
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• 2010

The rate of carbonation is usually low in the natural environment due to the low $CO_2$ concentration in the atmosphere. Therefore, investigation of carbonation is usually conducted under accelerated testing conditions so as to speed up the process. This study is to predict carbonation progress by mathematical model, based on the diffusions of $CO_2$ and its reaction with $Ca(OH)_2$ in carbonation progressing region, in the atmosphere. To predict of carbonation progress in the atmosphere, we adopted a diffusion coefficient of $CO_2$ that agreed well the experimental value obtained by the accelerated carbonation test. Consequently the model can predict the rate of carbonation of concrete exposed in the atmosphere regardless of finishing materials.