• Journal of dental hygiene science
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• v.13 no.3
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• pp.330-338
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• 2013

In order to explore microleakage in class V cavity based on different kinds of several dentin adhesive and composite resin, 2 kinds of composite resin was restored and exposed after applying 4 kinds of dentin adhesives. Deposited in methylene blue solution for 4 hours and cut in parallel with tooth longitudinal axis. By observing dye penetration level of enamel and dentin margins of each restored resin following conclusion was obtained. 1. In composite resin Filtek Z350XT Universal (3M/ESPE Dental Products, USA) in enamel margin, Easy Bond (3M/ESPE Dental Products) showed the lowest microleakage and this leakage was represented to be high in the order of Single Bond 2 (3M/ESPE Dental Products), Scotchbond Multi-Purpose (3M/ESPE Dental Products) and Cearfil SE Bond (Kuraray Medical Inc., Japan). In case of Filtek Z350XT Flowable (3M/ESPE Dental Products), Scotchbond Multi-Purpose showed the lowest microleakage and this leakage was represented to be high in the order of Single Bond 2, Clearfil SE Bond and Easy Bond. 2. In case of Filtek Z350XT Universal in dentin margin, Easy Bond showed the lowest microleakage and this leakage was represented to be high in the order of Scotchbond Multi-Purpose, Single Bond 2 and Clearfil SE Bond. In case of Filtek Z350XT Flowable, Scotchbond Multi-Purpose and Single Bond showed the lowest microleakage and this leakage was represented to be high in the order of Clearfil SE Bond and Easy Bond. 3. In all the groups excepting S-U group (Single Bond 2+Filtek Z350XT Universal), enamel margin showed more higher microleakage than that of dentin margin. 4. There was a difference between enamel and dentin margin among each group but it was not significant statistically (p>0.05). When summarizing this result, it is considered that composite resin and dentin adhesive could be applied selectively and particularly in case of applying 1-step self-etching dentin adhesive, this method would be advantageous for manipulation convenience and shortening of operation time.

• Journal of dental hygiene science
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• v.1 no.1
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• pp.46-52
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• 2001

The purpose of this study was to examine dental personnels' concern for health, their personal protection manner, and whether or not they were inoculated against hepatitis B and made an inquiry of patients about that. It's ultimately meant to serve as a basis for the preparation of an anti-infection guide for the protection of dental personnels against all sorts of infectious diseases. After a survey was conducted from March 29 through May 9, 2001, the following findings were obtained: (1) The dental personnel group that had worked for 5 to less than 7 years took health examination the most, with 71.4%, before joining the hospital, and 61.5% of those who had served for 9 years or more, the greatest percentage, took medical checkup after joining the hospital(P<0.05). (2) The largest percentage of being inoculated against the anti-B type hepatitis after employment was 71.4% of the dental personnels over 35, and 57.7% of those with 9-year or more working experiences. Therefore, their age and service term made a significant difference(P<0.05). (3) There was no significant gap in personal protection practices between the dental hygienists and nurse aids(P>0.05). But the use of safety goggles for treatment was not properly done, with just 1.48 on the basis of 3 points, whereas the use of mask was scored 2.40 and the use of gloves was scored 1.96. (4) After a narcotic was used once, the leftovers were wasted by 89.7% of the dental hygienists and 70.0% of the nurse aids. More dental hygienists wasted them(P<0.05). (5) For hand washing, antibiotic liquid soap was used by 19.3% of the dental hygienists and 10.0% of the nurse aids, which were both very low percentage. And just 37.2% of the dental hygienists utilized a disposable paper towel to dry their hands, and only 36.0% of the nurse aids used the same(P<0.05).

• Restorative Dentistry and Endodontics
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• v.26 no.5
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• pp.409-417
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• 2001

The purpose of this study was to investigate the influence of light irradiation over self-priming adhesive on dentin bonding. After acid etching the exposed dentin, a self-priming adhesive (Prime&Bond$^{\circledR}$NT dental adhesive system Dentsply DeTrey, GmbH, Konstanz, Germany) was applied and light irradiation was done for 20 sec with regular intensity (600 mW/$\textrm{cm}^2$) in group I and for 3 sec with ultra-high intensity (1930 mW/$\textrm{cm}^2$) in group III. No light irradiation was done over self-priming adhesive in groups II and IV. Composite resin was added on the self-priming adhesive and irradiated for 40 sec with regular intensity (600 mW/$\textrm{cm}^2$) in groups I and II and for 3 sec with ultra-high intensity (1930 mW/$\textrm{cm}^2$) in groups III and IV. To see the effect of light curing time on dentin bonding, another 3 group specimens were prepared. Without light-irradiation over self-priming adhesive, added composite resin was irradiated for 3, 6, or 12 sec with ultra-high intensity light. After bonded specimens were stored in 37$^{\circ}C$ distilled water for 24 hours, shear bond strength were measured using a universal testing machine (4202, Instron, Instron Co., U.S.A.) and fractured surfaces were examined under a stereomicroscope (SZ-PT Olympus, Japan). Statistical analysis were done with one-way, two-way ANOVA and chi-square test. The results were as follows : 1. The shear bond strengths from the groups irradiated over self-priming adhesive were significantly higher than those from the groups without irradiation (p<0.05). 2. There was no significant shear bond strength difference between regular intensity light irradiation groups and ultra-high intensity ones (p>0.05). 3. There was no significant shear bond strength difference among various irradiation time groups with ultra-high intensity ones (p>0.05). 4. In stereomicroscopic examination of fractured surfaces, adhesive-cohesive mixed failure mode was mostly seen in all groups, and there was no significant difference in failure mode among groups (p>0.05).

• Korea journal of population studies
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• v.21 no.1
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• pp.184-228
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• 1998

This study reviews the relationship between son preference and fertility behavior, and infant and chlid mortality in the context of fertility and mortality decline. In Korea the situation reveals that fertility can decline to a very low level even in the presence of strong son preference, but son preference has certain effects on fertility and childhood mortality. The effect of son preference on fertility increased as the level of fertility declined. Our findings show that son preference causes excess female childhood mortality both directly and indirectly through fertility. Also, in Korea, the analysis reveals that female children suffer excessively high level of mortality and part of the excess mortality is due to parents' behavior on family building related to the effort to secure the birth of a son.

• Journal of dental hygiene science
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• v.4 no.1
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• pp.13-20
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• 2004

The purpose of this study was to examine how dental hygienists health management and to what extent they used medical care services due to occupational diseases. It's ultimately attempted to improve the health care of dental hygienists and promote their health. After relevant literature and data were reviewed, a survey was conducted for five months from June through October, 2003. The subjects in this study were 160 dental hygienists who worked at dental hospital and clinics across the nation. And the collected data were analyzed. The findings of this study were as follows: (1) Concerning job-related health education experience, 83.1 percent, the greatest rate, had no experience to receive education, and the type of service made a significance difference to that(p<0.05). (2) As to in-house medical examination, 98.6 percent felt the need for medical examination, and 56.3 percent had ever their bodies examined. Their health examination experience was significantly different according to age(p<0.01), marital status(p<0.01), type of service(p<0.01), career(p<0.01) and yearly income(p<0.01). (3) Concerning how much they used hospitals after working as dental hygienists, 85.6 percent, the biggest group, had no experience to be hospitalized, and that was significantly different according to age(p<0.05), type of service(p<0.05), career(p<0.01) and yearly income(p<0.05). 51.9 percent had no experience to receive treatment as outpatients, and their career(p<0.01) made a significant difference to that. (4) As for how to cope with casual diseases, 34.4 percent, the largest group, visited pharmacies, and 32.5 percent, the next largest group, saw the doctors. In regard to herb restorative, 68.1 percent had no experience to take herb restorative, and that experience varied significantly with age(p<0.01), career(p<0.05) and annual income(p<0.01).

• Korean Journal of Weed Science
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• v.14 no.3
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• pp.199-211
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• 1994

Butachlor applied pre-emergence at 3.6kg ai/ha inhibited the growth and developments of shoot of barnyardgrass under dry condition, whereas rice was unaffected. Growth of rice and barnyardgrass under water condition was severely inhibited by treatment of butachlor but that of transplanted rice was not affected. The inhibition rate was higher under water condition, in broadcast rice and direct seeded rice than under dry condition, drilled rice and transplanted rice, respectively. The major anatomical response of stem of barnyardgrass seedling to butachlor under dry condition were partial reduction in thickness and collapse of leaf sheath, while not in rice. Broadcast rice on soil under water condition appeared reduction and constriction of leaf primordia thickness, and barnyardgrass formed tubular-like leaves and showed inhibited elongation of apical meristem. On the other hand, transplanted rice did not show these responses.

• Korean journal of applied entomology
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• v.47 no.2
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• pp.155-162
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• 2008

The Welsh onion beet armyworm, Spodoptera exigua (Hubner), has attacked Welsh onion and is now the most important pest of Welsh onion in southwestern Korea. The beet armyworm has a wide host range, occurring as a serious pest of vegetable and fields. The relatively high abundance of beet armyworm has stimulated frequent application of insecticides to foliage. Insecticide resistance is a major problem in management of this insect. Accordingly, pesticide application for the control of beet armyworm was tried in both the open field and in laboratory, using 4 synthetic compounds such as metaflumizone and chlorfenapyr, indoxacarb, flufenoxuron, emamectin benzoate. In the laboratory, each developmental stages from eggs, larva to pupa was tested against 4 insecticides. Against the eggs of welsh onion beet armyworm, there was no significantly different with each other. These tested chemicals no killing effect to eggs. However, the population of 1st larva hatched from eggs were reduced because they eaten the egg shell with residual insecticides. The tested insecticides were taken very high mortalities to 1st to 3rd larva of Welsh onion beet armyworm. Otherwise, there were decreased the death rate from 4th to 6th larva. On the other hand, their value of control effects were relatively good against Welsh onion beet armyworms in the field between 87.2 and 90.5% on 10 days after insecticide application.

• Journal of Bio-Environment Control
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• v.20 no.4
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• pp.399-405
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• 2011

In this study, we evaluated the fruit quality indices and the incidence of physiological disorders of Korean new pear cultivar 'Whasan' to determine appropriate harvest time for exportation and to enhance storability and shelf-life of the fruits during simulated exportation and extending market environment under different temperature conditions. In the experiment of simulated exportation headed for North America including Canada and U.S.A., the fruits transported at $1^{\circ}C$ showed less weight loss than those of $5^{\circ}C$. Market temperature appeared as a key factor for keeping freshness of exported pear fruits rather than transportation temperature. Quality factors such as high flesh firmness and low incidence of fruit rot and physiological disorders including core breakdown and pithiness were attained at the fruits maintained at $18^{\circ}C$ when we compared with $25^{\circ}C$. The fruits of harvested early maturity at 135 day after full bloom showed 28.6 N of flesh firmness when the fruits stored at $1^{\circ}C$ of transportation and $18^{\circ}C$ of market temperature, while the fruits progressed $5^{\circ}C$ of transportation and $25^{\circ}C$ of market temperature dropped to 24.2 N during 30 days of shelf life. Also, a high incidences of physiological disorders and of fruit decay rates were obvious in the fruits distributed at $25^{\circ}C$ were observed approximately two times higher than the those of $18^{\circ}C$. Therefore, temperature management during marketing resulted as an important point for maintaining fruits quality in the process of pear fruit exportation.

• Journal of Yeungnam Medical Science
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• v.2 no.1
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• pp.135-147
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• 1985

The authors studied neuroticism, using Eysenck's Maudsley Personality Inventory (MPI), in 3,893 male college students and 1,976 female college students of Yeungnam University. There was significant difference in the mean averages of total neuroticism scores between male and female students, male students scored $13.45{\pm}7.44$, female students scored $16.89{\pm}7.19$. The items relating to (16) Do you sometimes feel happy, sometimes depressed, without any apparent reason? (38) Do you daydream a lot? (1) Do you have dizzy turns? (2) Do you get palpitations or thumping in your heart? and (35) Do you worry about your health? were scored highly in male, and the items relating to (16) Do you sometimes feel happy, sometimes depressed, without any apparent reason? (1) Do you have dizzy turns? (38) Do you daydream a lot? (8) Do you worry too long over humiliating experiences? (9) Do you consider yourself rather a nervous person? were scored highly in female. Three hundreds and ninety eight male students (10.3%) showed seriously high neuroticism scores of 24 or higher, while 256 female students (13.0%) showed high neuroticism scores of 26 or higher. In a comparison between male students in different school grades, freshman showed the highest level of neuroticism scores. Among the psychosocial factors, there were strong tendencies toward higher neuroticism scores in the students who were dissatisfied with their colleges or departments, and who had pessimistic views of self-image in the past, present, or future in both groups. The male students whose educational fees were paid by their parents, and whose spending money per month was under 10,000 won, showed higher neuroticism scores. The female students whose educational fees were paid by their brothers or sisters, and whose maturation locations were U-P, and who resided in dormitory or other residencies, showed higher neuroticism scores.

• Food Science and Preservation
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• v.19 no.3
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• pp.354-360
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• 2012

The effect of the wavelength of the light emitted by the light-emitting diode (LED) on the growth characteristics and physicochemical and sensory qualities of Pleurotus eryngii were investigated. Pleurotus eryngii were grown under different light sources: blue light (450 nm), red light (650 nm), green light (525 nm), UV-A (365 nm), and mixed light ($B^*R$, $B^*G$, $R^*G$, $B^*R^*G^*UV-A$). The quantity of LED light was set up at 50% (LED: 64.9-108.0 $pmolm-2{\cdot}s-1$;fluorescentlight:11.7lux). Fluorescent light was used as control. There were no significant differences in the flesh firmness. In the case of the Pleurotuseryngii cultivated under red, green, and mixed light ($R^*G$), the color of the pileus and the length of the stipe were similar to those of the control group. The sensory scores were not significantly different between the LED lights (red, green, and $R^*G$) and the control. Among the three LED light conditions, the sample cultivated under red light recorded the highest score. The samples under UV-A, blue, and mixed light ($B^*R$, $B^*G$, $B^*R^*G^*U$) had a dark pileus color and had a short stipe. These results showed that the wavelength of LED light affected the growth and quality characteristics of Pleurotus eryngii, and that using red LED light is preferable for the cultivation of Pleurotus eryngii with better quality.