• Journal of dental hygiene science
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• v.5 no.4
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• pp.233-238
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• 2005

The study was intended to investigate elementary schoolers' oral health status according to whether the school have and manage an school oral health clinic or not in order to provide useful information for continuously developing the school oral health clinic 1,163 children in Hwasan elementary school in Hwasung city and 485 children in S elementary school in the same locality were selected as the experimental group and the control group, respectively, and orally examined from May 1st to 30th, 2004. The findings from the oral examination were as follows. 1. DMF rate was higher in the higher grades in both the groups. The rate was lower in the experimental group with 45.1% of the children than in the control group with 65.3% of the children. 2. DMFT rate also were higher as the grades were higher in both the groups. The ratio was lower in the experimental group with 30.4% of the children than in the control group with 44.6% of the children. 3. DMFT index was 1.0 in number in the experimental group and 1.6 in the control group. Index increase from the 1st grade to the sixth grade was also more positive in the experimental group. 4. DT rate was a little higher in the experimental group in the first graders, but comparatively decreased to the grades while increased in the control group. In the sixth graders, the rate was 42.4% in the experimental group and 87.7% in the control group, the former was less than the latter by about 50% point. 5. FT rate was a little higher in the control group for the first graders but increased in the experimental group to the grades. The rate in the sixth graders was higher by more than double in the experimental group. Based on the above findings, the region of the study had better oral health statistics than in other regions. The operation of school oral health clinics that provide dental health care to children at the right time seems to contribute to enhancing their dental health status by preventing against dental diseases and changing their relevant knowledge, attitude and behaviors. In the future, more school oral health clinics should gradually be prepared to push ahead with a sustained, extensive dental health project geared toward school-aged children. To make it happen, dental hygienists who are professional medical personnels should be taken advantage of, and in order to beef up the efficiency of preventive measures and oral health education, the best dental health care services should be offered by harnessing dental hygienists and dentists who work at public dental clinics run by local governments.

• The Korean Journal of Pesticide Science
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• v.14 no.1
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• pp.10-15
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• 2010

Most pesticides are poorly soluble in water and must be dissolved in a solvent carrier before being added to the test medium on aquatic toxicity test. The concentration of solvent is critical to the success of a test. This study were conducted to recommend possible organic solvents which have good solubility for pesticides and low toxicity to Korean native water flea to establish new standard toxicity test methods using Korean native water flea for ecological risk assessment of pesticide. Four Korean freshwater cladocerans, Daphnia obtusa, Daphnia sp., Moina macrocopa and Simocephalus vetulus were exposed to 10 different organic solvents during 48 hours to evaluate their toxic response to solvents. Ethyl acetate was the most toxic to cladocerans tested. Although ethyl ether was the least toxic to cladocerans tested, it may not adequate as possible solvent in aquatic toxicity test due to high volatility and low water solubility. In conclusion, acetone, methanol, ethanol and acetonitrile which has low toxicity as well as good water solubility are recommended as optimal organic solvent to use in aquatic toxicity tests with Korean native cladocerans tested.

• Journal of Korean society of Dental Hygiene
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• v.8 no.4
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• pp.115-125
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• 2008

The purpose of this study was to examine the relationship between the Dentocult SM and LB scores of students and their DMF rate. The subjects in this study were 134 special school students in south Gyeong-sang province. After they were tested to find out their, they received tooth brushing education and preventive treatment. The test, education and treatment were all conducted from March 17 to April 9, 2008. Their oral state was checked and recorded by using a mirror and explorer, and then the data on oral state were analyzed to their DMFT, DT, FT and MT rates. All the collected data were analyzed with SPSS 15.0 for Windows program, and independent-samples t-test, one-way ANOVA and crosstabs analysis were implemented to see what differences their disability type, gender, Dentocult-SM scores and Dentocult-LB scores made. The findings of the study were as follows: 1. As for connections between disability type and DMFT rate, the students with mental retardation were similar to the other students in that regard. The mentally retarded students had higher DT and FT rates than the other students, and the MT rate of the latter was higher than that of the former. 2. Concerning the relationship of gender to DMFT and DT rates, the girls had larger DMFT and DT rates than the boys, and the FT and MT rates of the boys were higher than those of the girls. 3. As to links between Dentocult SM scores on the tongue and DMFT, the students whose bacteria was mildly activated had the highest DMFT rate, and the students who had a severely activated bacteria had the highest DT and FT rates. Those who had a moderately activated bacteria had the highest MT rate. 4.Regarding the connection of Dentocult SM scores on maxillyright molar to DMFT and DT rates, the students whose bacteria was severely activated had the highest DMFT and DT rates. Those who had no activated bacteria had the largest FT rate, and the students who had a mildly activated bacteria had the highest MT rate. 5.Regarding the connection of Dentocult SM scores on maxillyleft molar to DMFT and DT rates, the students whose bacteria was severely activated had the highest DMFT and DT rates. Those who had no activated bacteria had the largest FT rate, and the students who had a mildly activated bacteria had the largest MT rate. 6. Regarding the connection of Dentocult SM scores on mandibularright molar to DMFT and DT, FT rates, the students whose bacteria was severely activated had the highest DMFT and DT, FT rates. Those who had a moderately activated bacteria had the highest MT rate. 7. Regarding the connection of Dentocult SM scores on mandibularleft molar to DMFT and DT rates, the students whose bacteria was mildly activated had the highest DMFT and DT rates. Those who had no activated bacteria had the largest FT rate, and the students who had a moderately activated bacteria had the highest MT rate. 8. Regarding the connection of Dentocult LB scores to DMFT and DT rates, the students whose bacteria was severely activated had the highest DMFT and DT rates. Those who had no activated bacteria had a moderately FT rate, the students who had a mildly activated bacteria had a mildly MT rate.

• Membrane Journal
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• v.6 no.3
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• pp.157-165
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• 1996

Polysulfone(PS) membranes were prepared from homogeneous PS solutions by the phase inversion technique. When propionic acid(PA) was added into a casting solution of n-methylpyrrolidone(NMP) and PS, precipitation rate of the solution film was accelerated. This kind of acceleration was consistent, even though a precipitating nonsolvent was changed from water to isopropanol. These phenomena were caused by decrease of nonsolvent tolerance in the casting solution due to addition of PA. PS powder was prepared by precipitation of a 3wt% solution in dimethylformamide(DMF) using ethanol as nonsolvent. Gas adsorption analysis of the powder showed that the capillary condensation sites were found in the powder structure. Membranes prepared from PS solution(15wt%) in NMP had the following characteristics of gas adsorption and water permeation. In gas adsorption analysis, the membrane precipitated using isopropanol showed low uptake of nitrogen gas and the capillary condensation sites were not found. On the contrary, a significant amount of the capillary condensation sites was found in the membrane coagulated by water, which was related to increase of nitrogen uptake. tn the membrane prepared froin the solution including PA, an increase of the Henry's law sites and the Langmuir sites was not found clearly. However, the capillary condensation sites were significantly increased, and the water transport also increased.

• Journal of dental hygiene science
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• v.13 no.3
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• pp.271-280
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• 2013

This study aims to analyze the effects of tooth-brushing facilities (TBF) at middle schools that installed TBF in 2012 as part of the oral health project in Seongdong-gu, Seoul. The subjects were the first graders at A middle school that installed TBF previously and B middle school that installed TBF in 2012. The results are as follows: DMFT, DMFS and CPI didn't show significant difference by schools (p>0.05), but code (0) was higher and code (2) was lower in female students than male students (p<0.05). As to PHP index, the students at A school with TBF indicated better oral hygiene (p<0.01). In the research on before and after installing TBF, the oral hygiene was improved significantly more after the installation than before (p <0.01). In the comparison on the oral health-related behavior, the percentage of not brushing after lunch was higher B school than A school and the frequency of toothbrushing after lunch was higher A school than B school (p<0.01). About the reasons why not to brush after lunch, there was difference in 'lack of the place' as A school showed 2.6% while B school without TBF indicated 14.2% (p<0.01). About the changes of the oral health-related behavior before and after TBF installation, the percentage of not brushing after lunch increased from 78.7% to 83.8% after the installation. The average frequency of tooth-brushing after lunch for one week also decreased from 0.50 to 0.34 (p>0.05). Among the reasons why not to brush after lunch, 'lack of the place' significantly reduced, but 'because other friends don't do it' increased greatly after the installation (p <0.05). Only with the improvement of oral health knowledge, we cannot expect either clinical or behavioral significance. Not only schools but policies of governmental agencies and financial support, cooperation of community-related groups for program development and evaluation will contribute altogether to helping teenagers to habitualize proper oral health management.

• Archives of Pharmacal Research
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• v.21 no.4
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• pp.458-464
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• 1998

Search for a new $\alpha$-methylene-$\gamma$-butyrolactone-bearing 6-substituted purine as a potental antitumor agent has led to synthesize seven, hitherto unreported, $5^1$-Methyl-$5^1$-[(6-substituted-9H-purin-9-yl)methyl]-$2^1$-oxo-$3^1$- methylenetetrahydrofurans (H, Cl, l, $CH_3$, $NH_2$, SH, >C=O) (6a-g). These include $5^1$-Methyl-$5^1$-[(9H-purin-9-yl)methyll-$2^1$-oxo-$3^1$ -methylenetetrahydrofurans (6a), $5^1$-Methyl-$5^1$-[(6-chloro-9H-purin-9-yl)methyl]-$2^1$-oxo-$3^1$-methylenetetrahydr ofurans (6b), $5^1$-Methyl-$5^1$-[(6-chloro-9H-purin-9-yl) methyl]-$2^1$-oxo-$3^1$-methylenetetrahydrofurans (6c), $5^1$-Methyl-$5^1$-[(6-methyl-9H-purin-9-yl) methyl]-$2^1$-oxo-$3^1$-methylenetetrahydrofurans (6d), $5^1$-Methyl-$5^1$-[(9H-adenin-9-yl)methyll-$2^1$-oxo-$3^1$-methylenetetrahydrofurans (6e), $5^1$-Methyl-$5^1$-[(6-mercapto-9H-purin-9-yl) methyl]-$2^1$-oxo-$3^1$-methylenetetrahydrofurans (6f) and $5^1$-Methyl-$5^1$-[(9H-hypoxanthin-9-yl)methyll-$2^1$-oxo-$3^1$-methylenetetrahydrof urans (6g) which were made by the Reformatsky-type reaction of ethyl $\alpha$-(bromomethyl) acrylate with the corresponding (6-substituted-9H-purin-9-yl)-2-propanone intermediates (5a-g). These ketone intermediates 5a-g, 1-(9H-purin-9-yl)-2-propanone (5a), 1-(6-chloro-9H-purin-9-yl)-2-propanone (5b), 1-(6-iodo-9H-purin-9-yi)-2-propanone (5c), 1-(6-methyl-9H-purin-9-yl)-2-propanone (5d), 1-(9H-adenin-9-yl)-2-propanone (Se), 1-(6-mercapto-9H-purin-9-yl)-2-propanone (5f), and 1-(9H-hypoxanthin-9-yl)-2-propanone (5g) were directly obtained by the alkylation of the 6-substituted purine bases with the chloroacetone in the presence of $K_2$$CO_3$ (or NaH) under DMF (or DMSO). The preliminary in vitro cytotoxcity assay for the synthetic .alpha.-methylene-y-butyro-lactone compounds (6a-g) were determined against three cell lines (PM-3A, P-388, and K-562) and showed the moderate antitumor activity ($IC_50$ ranged from 1.4 to 4.3 $\mu\textrm{g}$/ml) with the compound $5^1$-methyl-$5^1$ -[(9H-hypoxanthin-9-yl)methyl]-$2^1$-oxo-$3^1$-methylenetetrahydrofuran (6g) showing the least antitumor activity.