• Journal of dental hygiene science
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• v.15 no.2
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• pp.238-245
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• 2015

Dentinal hypersensitivity is a type of dental pain that occurs when various stimuli are applied to exposed dentin lesions. If the symptoms of dentinal hypersensitivity continue, the dentin is exposed and the hypersensitivity may become a periodontal disease or root caries due to bacterial infection. Therefore, the clinical goal of the present study is to reduce the pain of the patient suffering from dentinal hypersensitivity by developing antimicrobial hypersensitivity treatments and to improve oral hygiene. We prepared chlorhexidine, tetracycline, cetylpyridinium chloride, gallic acid loaded desensitizer by adding 0.1%, 0.5%, 1.0%, and 2.0% chlorhexidine, tetracycline, cetylpyridinium chloride, gallic acid to desensitizer (Micro Prime; Denville and Hurri Seal; Beutlich), and antibacterial effect, and cytotoxicity. The antibacterial test by using Staphylococcus aureus (SA. ATCC 6538, FDA 209) showed that the antibacterial effect of all experimental groups was significantly higher than that of control group (p<0.05). Cytotoxicity test by using agar diffusion assay indicated that Micro Prime showed mild toxicity, Hurri Seal showed severe toxicity and this cytotoxicity is supposed to be caused by one of desensitizer components showing weak antibacterial effect.

• Korean Journal of Food Science and Technology
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• v.34 no.2
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• pp.303-310
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• 2002

An optimization for fermentation processes to make lactic acid juice with extracts from apples, carrots, celery, watercress, jujube and lycii (3 : 3 : 1 : 1/2 : 1 : 1/2) using co-cultures of Leuconostoc mesenteroides, Lactococcus lactis and Lactobacillus cellobiosus isolated from Dongchimi had been investigated on the emphasis of composition of sugars and sodium chloride at various temperatures. The concentration of sugars less than 25% and salt less than 0.8% did not affect remarkably the cell growth of lactic acid bacteria and acid formation during fermentation. The fermenting juice showed increases in the population of lactic acid bacteria and acidity, and decreases in population of coliform bacteria and sugar concentration with high cultural temperature. At $25^{\circ}C$ viscous substance was not formed as it had at $15^{\circ}C$. The optimum composition, based on the sensory evaluation, was determined to be oligosaccharide and 0.2% for sodium chloride. It took 3 days to produce the most preferable juice of pH 3.62 at $25^{\circ}C$. At the optimal state the fermented juice showed viable cell counts (cfu/mL) of exponential numbers 8 for lactic acid bacteria and 4 for yeast. Coliform bacteria which had been $5.6{\times}10^2\;cfu/mL$ at the beginning of fermentation were not detected.

• Journal of Environmental Science International
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• v.21 no.8
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• pp.1015-1021
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• 2012

Formation of disinfection by-products (DBPs) including trihalomethans (THMs), haloacetic acid (HAAs), haloacetonitriles (HANs) and others from chlorination of algogenic organic matter (AOM) of Microcystis sp., a blue-green algae. AOM of Microcystis sp. exhibited a high potential for DBPs formation. HAAs formation potential was higher than THMs and HANs formation potential. The percentages of dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA) formation potential were 43.4% and 51.4% in the total HAAs formation potential. In the case of HANs formation potential, percentage of dichloroacetonitrile (DCAN) formation potential was 97.7%. Other DBPs were aldehydes and nitriles such as acetaldehyde, methylene chloride, isobutyronitrile, cyclobutanecarbonitrile, pentanenitrile, benzaldehyde, propanal, 2-methyl, benzyl chloride, (2-chloroethyl)-benzene, benzyl nitrile, 2-probenenitrile and hexanal.

• Membrane and Water Treatment
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• v.9 no.6
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• pp.385-392
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• 2018

Poly vinyl chloride (PVC) was chemically modified, and used for ultrafiltration to analyze the performance. Non-solvent induced phase separation (NIPS) method was used to prepare membranes. The neat PVC membrane was casted and used as a control membrane. Modified membrane was prepared by reacting PVC with ethanolamine (EA) in the casting solution (labeled as CM-PVC). Pure water permeability (PWP) was evaluated by measuring pure water flux. Humic acid was used as model foulant solute to analyze flux and rejection ability of membranes. Flux and rejection data of neat and modified membranes were compared to prove the improvement in the filtration performance. The experimental results showed that for PVC and CM-PVC, PWP was calculated to be ~64 and ${\sim}143L/m^2{\cdot}h$, respectively, and the rejection of humic acid was found to be 98% and 100%, respectively. TGA was carried out to analyze the effect of chemical modification on the thermal stability of polymer. FT-IR analysis was another characterization technique used for the comparative study.

• Journal of Pharmaceutical Investigation
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• v.24 no.3
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• pp.109-113
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• 1994

Effects of various formulation factors using $L_8$ orthogonal arrays with the stability of doxorubicin hydrochloride injections(DHls) were investigated. The degradation of DHI may be occured by pH, temperature, light and metal ions. It is known that DHI should be stored on refrigerated condition of $4{\sim}8^{\circ}C$ because of its unstability on the room temperature. The employed factors were sodium chloride as isotonic solution, sodium bisulfite or sodium pyrosulfite as an antioxidant, disodium edetate as a chelating agent, methyl parahydroxybenzoate as a dissolution time shortening agent, and hydrochloric acid or citric acid as a pH adjusting agent at $22^{\circ}C$. From the results of $L_8$ orthogonal arrays, an optimal formula, including sodium chloride, disodium edetate, sodium bisulfite and hydrochloric acid, was obtained and the shelf-life of the formula was determined as 560 days approximately.

• Textile Coloration and Finishing
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• v.27 no.4
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• pp.229-244
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• 2015

The effects of synthesis conditions on characteristics of the calcium-azo complex pigment, C.I. Pigment Red 57:1, were studied. It was mainly considered that the industrially required synthesis conditions for lowering electrical conductivity of the pigment solution keeping pigment quality such as particle size and color characteristics. Three parameters were chosen as control factors during the synthesis. The first was the amount of hydrochloric acid added to transform sodium nitrite into nitrous acid. The second was the amount of calcium chloride added to insolubilize the synthesized azo dye. The final factor was pH control during the coupling reaction. The electrical conductivity and pigment aggregate particle size were dependent on the amount of hydrochloric acid and calcium chloride. Higher HCl concentration gave brighter yellowish-red color because of smaller particle aggregate size and narrower size distribution. Amount of charged ions in the synthesis process might affect the "lake" formation resulting different particle aggregate size and color shade.

• Horticultural Science & Technology
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• v.34 no.6
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• pp.898-911
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• 2016

Sugars play many important roles in plant metabolism and directly influence fruit quality. The effects of two edible coatings, 2% calcium chloride and 1% pullulan, on sugar metabolism in postharvest Huangguan pear fruit were investigated during cold storage. The respiration rate, sugar content and composition, sucrose metabolism enzyme activities [acid invertase (AIV), neutral invertase (NI), sucrose synthase (SS), and sucrose phosphate synthase (SPS)] and expression of the AIV gene were analyzed during storage at $0^{\circ}C$ for 210 days. Coating treatments slowed the decrease of sucrose and hexose, the respiration rate, and the activities of AIV, NI, SS and SPS, thus maintaining high total soluble solids (TSS) and titratable acid (TA) contents in the fruit. There were no significant differences in AIV expression or activity between the treated and control groups of fruits. Both of the coatings could inhibit the activities of sucrose-cleaving enzymes, thus slowing the decrease of sugar content and maintaining high fruit quality during cold storage.

• Environmental Engineering Research
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• v.22 no.2
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• pp.149-156
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• 2017

Chromium(III) recovery from tanning wastewater by means of adsorption on activated carbon and elution with sulfuric acid was studied. Tests were carried out at laboratory scale on an effluent of industrial origin. Initially, proteinaceous materials and fats were separated via sieving followed by ultrafiltration. The chemical composition of the sample thus precleansed was (in g/L): 1.09 chromium(III); 10.36 sulfate; 11.10 sodium; 9.57 chloride; 0.40 proteinaceous materials; and 0.20 fats. Adsorptions were made at 20, 30, and $40^{\circ}C$, establishing what temperature favored chromium(III) uptake. At $40^{\circ}C$, the maximum cation fixation was 40.2 mg/g, and the lowest content in an equilibrium solution was 3.9 mg/L. As regards sodium, chloride, and sulfate, the concentrations before and after the treatment were similar. Likewise, it was found that protons were also retained, modifying the pH of the liquid medium. Adsorption isotherms were analyzed using the Langmuir, Temkin, and Freundlich models. Finally, the extraction of the adsorbed tanning agent with sulfuric acid was evaluated. A recovery of 96.5% was achieved with 0.9 N at $70^{\circ}C$ (13.23 g/L $Cr^{3+}$; 42.98 g/L sulfate; and 0.40 g/L NaCl).

• Journal of the Korean Chemical Society
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• v.37 no.1
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• pp.136-140
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• 1993

New synthetic method for diethyl N-[4-{[(2,4-diamino-6-yl)methyl]-amino}benzoyl]-L-glutamate(10) which is an intermediate of methotrexate is described. p-Nitrobenzoyl-L-glutamate was obtained via a two-step sequence which involves condensation of p-nitrobenzoyl chloride with diethyl-L-glutamate and Fischer esterification reaction with ethanol. Reductive methylation of diethyl-p-nitrobenzoyl-L-glutamate were carried out by reaction with formic acid and paraformaldehyde in the presence of $PtO_2$ catalyst and yielded diethyl N-(4-methylaminobenzoyl)-L-glutamate(7). It was followed by allylation and iodoazidozation to give the diethyl-p-[N-(2-azido-3-iodopropyl)-N-methyl]aminobenzoyl-L-glutamate(9). The cyclization reaction of compound(9) with 2,4,5,6-tetraaminopyrimidine was carried out by intermolecular nucleophilic substitution to give the desired methotrexate diethylester.

• Mycobiology
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• v.43 no.3
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• pp.203-209
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• 2015

Three new fungal species of the genus Mortierella, Mortierella zychae, Mortierella ambigua, and Mortierella indohii, have been reported in Korea. The fungi were encountered during a study on the fungal community of soil samples collected from different locations in Korea. The species were identified based on molecular and morphological analyses. This study presents detailed descriptions of the morphological observations and molecular phylogenetic analysis of these three fungi. All three species were found to be sensitive to triphenyltetrazolium chloride staining. M. zychae demonstrated the highest intensity of mycelial staining, indicating that this species has the highest potential to produce arachidonic acid of the three species. The staining results indicated that the newly recorded species could potentially be useful for arachidonic acid production.