• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.477-488
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• 1996

The purposes of this study were to measure the solubility of the stannous fluoride experimentally, to find a method for improving the solubility of the stannous fluoride, and to observe the effect of longterm storage on the variation of the concentration of fluoride in the stannous fluoride solutions. By adding such materials as antiseptics, dye, flavor, and tastes to solution, the variation of the fluoride concentration was also observed. Ten groups of 0.4% stannous fluoride solutions to which glycerine, sodium chloride, chlorhexidine, dye, flavor, xylitol, and sorbitol were added were prepared. The measurements were carried out by direct calibration. The obtained results were as follows. 1. Effect of adding glycerine as solvent. : The solubility of stannous fluoride increased in the case of adding glycerine. By increasing the glycerine concentration, the fluoride level in stannous fluoride solution also increased. 2. Effect of adding sodium chloride and chlorhexidine. : Comparing to the case of pure water, low fluoride level was measured in case of adding sodium chloride and high fluoride level was measured in case of adding chlorhexidine. 3. Effect of adding erythrosin as dye and banna essence as flavor. : Adding erythrosin and banna essence didn't affect fluoride level. 4. Effect of adding xylitol and sorbitol. : The effects of xylitol and sorbitol were nearly the same as the effect of adding erythrosin and banna essence.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09a
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• pp.276-277
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• 2006

In order to accelerate the sintering of Al-Bronze powder covered with passive oxide film, we focused on the way to add Al-Ca fluoride consisting of $AlF_3$ and $CaF_2$, examined the effect of the $CaF_2$ mixing rate in Al-Ca fluoride, the amount of the added Al-Ca fluoride and the sintering temperature on sintering properties of Al-Bronze powder and considered the mechanism of the sintering acceleration. Al-Bronze powder was sintered most effectively by adding Al-Ca fluoride with the $CaF_2$ mixing rate of 20mass%. If the amount of added fluoride was over 0.05mass% and the sintering temperature was over 1123K, the sintering acceleration of the Al-Bronze powder appears. Regarding the mechanism of the sintering acceleration, it was presumed that $Al_2O_3$ film on the surface of the Al-Bronze particles was removed in the process of the formation of gaseous AlOF by the reaction with $AlF_3$, and the reaction was accelerated further by the presence of the liquid phase which is formed in Al-Ca fluoride.

• Journal of Korean Society of Water and Wastewater
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• v.10 no.4
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• pp.73-84
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• 1996

Fluoride was first introduced into the drinking water of residents of Grand Rapids, Michigan in 1945 for the prevention of dental caries. Ever since, growing numbers of communities favor fluoridation. Now, over 7000 communities in the United States are adding F(0.7~1.2ppm) to their drinking water. The most effective to prevent tooth decay is putting lower concentrated fluoride(F, 0.7~1.2ppm) into drinking water. However, exact fluoride injection amount have not been decided, because the research of the fluoride injection effect was insufficient. Therefore, after separating fluoridation and non-fluoridation into public water supplies, we investigated concentration of fluoride, alkalinity, Al, Ca, Mg, evaporation residuals in APT, domestic, commercial area. Then, we decided allowable concentration of fluoride, injection point of fluoride in water supply system, cost effectiveness.

• Journal of Environmental Science International
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• v.28 no.11
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• pp.943-950
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• 2019

The purpose of this study was to probe the influences of NaF oral administration on a dose-effect relationship between fluoride levels of serum enzyme activity such as alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) in rats fed experimental diets for 5 weeks. All groups increased the activity of serum ALP, AST, ALT, and LDH levels with increasing NaF. In addition the fluoride levels of serum and organ tissues (liver, brain, heart, lung, kidney) in oral NaF groups (NF3~NF50) were significantly increased by adding sodium fluoride in comparison with normal diet group (ND) (p<0.05). These results, a high concentration of sodium fluoride was determined that the toxicity to various organ tissues.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.1
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• pp.85-89
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• 2000

There has recently been some trials to add the fluoride-releasing property to existing fissure sealants and some of them are already commercially available. But, some questions mat naturally be arisen regarding the potential decrease of physical properties by adding the fluoride despite its new caries-inhibiting abilities. This study was performed for the purpose of comparing the shear bond strengths of conventional composite sealant, Fluoride-releasing sealant and glass ionomer sealant, and obtained the results as fellows. 1. Two kinds of composite sealants (Helioseal and Teethmate-A) showed slightly higher bond strength than Fluoride-releasing sealant(Teethmate-F) without any significance(p>0.05). 2. Class ionomer sealant (Fuji III) was much lower than composite sealant in shear bond strength(p<0.05). 3. With the result of this study, it was found that there is little effect on retentive properties of sealants by adding fluoride to amplify the caries-inhibiting properties.

• Fisheries and Aquatic Sciences
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• v.15 no.3
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• pp.203-207
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• 2012

The amount of fluoride removed from Antarctic krill via organic acid extraction depends on the extraction time, concentration, extraction volume, and the nature of the acid itself. The fluoride content in Euphausia superba was determined by measuring the concentration of fluoride ion in acidic extracts using an ion-selective electrode. The best results were obtained by adding 50 mL of 0.01 M citric acid to 0.3-0.5 g of krill and extracting for 5 min. Under these conditions, recoveries of fluoride from frozen whole krill and krill meat were 95.6-99.5% and 97.5-101.3%, respectively. The dry basis fluoride contents of krill by-product, krill meat and the boiled krill were 705, 298, and 575 ppm, respectively. These levels were significantly reduced by citric acid extraction.

• Environmental Analysis Health and Toxicology
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• v.13 no.1_2
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• pp.19-26
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• 1998

In Korea, fluoride was first introduced into the drinking water of residents of Jinhae, KyungNam in 1981 for the prevention of dental caries. Ever since, growing numbers of communities favor fluoridation. The mechanism of F prevention of tooth decay is well known: fluoride ions substitute for hydroxyl ions in hydroxyapatite of hard tissues, which result in crystal perfection, with consequent reduction in dental caries. Soluble fluorides such as sodium fluoride are almost completely absorbed from the gastrointestinal tract. However, the presence of divalent or trivalent cations such as aluminum, magnesium, and calcium that can complex with F can reduce the degree of absorption. In U.S.A., over 7000 communities are now adding F to their drinking water. However, some portion of population oppose fluoridation, voicing both concern about the safety of fluoridation as well as for personal choice. Thus, This paper reviews the interaction of fluoride and cations as well as fluoride and suggests possible problems associated with fluoridation, a controversial issue.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.4
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• pp.210-217
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• 2015

Fluoride removal by acid and heat treated red mud were studied in batch and column system regarding contact time, initial concentration, pH, adsorbent dose, and filter depth. The results showed that acid treated with 0.8 M HCl, had highest adsorption capacity of fluoride and adsorption capacity decreased as heat treatment temperature increased. Sorption equilibrium reached in 30 min at a initial concentration of 50 mg-F/L but 1 h was required to reach the sorption equilibrium at the initial concentration of 500 mg-F/L by 0.8 M acid treated red mud (0.8 M-ATRM). Equilibrium adsorption data were fitted well to Langmuir isotherm model with maximum fluoride adsorption capacity of 23.162 mg/g. The fluoride adsorption decreased as pH increased due to the fluoride competition for favorable adsorption site with $OH^-$ at higher pH. Removal percentage was increased but the amount of adsorption per unit mass decreased by adding the amount of 0.8 M-ATRM. It was concluded that the 0.8 M-ATRM could be used as a potential adsorbent for the fluoride removal from aqueous solutions because of its high fluoride adsorption capacity and low cost.

• Journal of Radiopharmaceuticals and Molecular Probes
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• v.5 no.1
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• pp.48-53
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• 2019

A bone metastasis is an important factor for prognosis and treatment of breast or prostate cancer patients. [$^{18}F$]Sodium fluoride ([$^{18}F$]NaF) is a PET radiopharmaceutical that can detect bone metastasis. Conventional [$^{18}F$]NaF production process included radioactive metal impurities because the product was prepared by adding saline after beam irradiation to $[^{18}O]H_2O$. In this study, we apply the method of removing radionuclidic impurities. To meet the criteria prescribed by GMP in quality control, we designed the custom-made [$^{18}F$]NaF automatic module. The mean radiochemical yield was $82.1{\pm}4.4%$ (n = 32) productions for 3 years) and the total preparation time was 4 min. The final produced [$^{18}F$]NaF solution meets the USP criteria for quality control. Thus, this fully automated system is validated for clinical use.

• Journal of Environmental Science International
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• v.27 no.11
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• pp.999-1005
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• 2018

The purpose of this study was to probe the influences of krill (Euphausia superba) meal with NaF oral administration on a dose-effect relationship between fluoride levels of krill meal and serum enzyme activity such as alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) in rats fed experimental diets for 5 weeks. There were no significant decreases in the activities of ALP, AST, ALT, and LDH in sera among krill meal diet groups (KF10, KF20, KF30). However, these groups were significantly (p<0.05) lower enzyme activities than normal diet (ND) plus NaF 10 mg group (NF). The fluoride levels of serum and organ tissues (liver, brain, heart, lung, kidney) in NaF 10 mg groups (NF, KF10, KF20, KF30) were significantly increased by adding krill meal in comparison with normal diet group. The results indicate that a difficult to found toxicity to the tissues from krill meal diet groups.