• The Journal of Korean Academy of Prosthodontics
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• v.50 no.2
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• pp.112-118
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• 2012

Purpose: The purpose of this study was to evaluate the difference in shear bonding strength between resin cements to dental materials when a universal primer (Monobond plus) was applied in place of a conventional primer. Materials and methods: Four groups of testing materials: gold alloy (Argedent Euro, n = 16), non precious metal (T-4, n = 20), zirconia (Cercon, n = 20) and glass ceramic (IPS e.max press, n = 20), were fabricated into discs, which were embedded in an acrylic resin matrix. The gold alloy specimens were airborne-particle abraded, 8 of the specimens were coated with Metal primer II, while the remaining 8 specimens were coated with Monobond plus. The non precious and zirconia specimen were airborne-particle abraded then, the control group received Alloy primer coating, while the other was coated with Monobond plus. Glass ceramic specimens were etched. 10 specimens were coated with Monobond-S and the remaining specimens were coated using Monobond plus. On top of the surface, Multilink N was polymerized in a disc shape. All of the specimens were thermal cycled before the shear bonding strength was measured. Statistical analysis was done with Two sample $t$-test or Mann-Whitney U test (${\alpha}$=.05). Results: There were no significant differences in bonding strength depending on the type of primer used in the gold alloy and glass ceramic groups ($P$>.05), however, the bonding strengths of resin cements to non precious metal and zirconia groups, were significantly higher when the alloy primer was used ($P$<.05). Conclusion: Within the limitations of this study, improvement of universal primers which can be applied to all types of restorations is recommended to precious metals and zirconia ceramics. But, the bond strengths of non precious metals and zirconia ceramics were significantly lower when compared to a 10-MDP primer. More research is needed to apply universal primers to all types of restorations.

• The Korean Journal of Malacology
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• v.29 no.1
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• pp.51-63
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• 2013

To assess the effect of environmental factors on the sustainability of cultured production shellfish, we investigated the habitat characteristics of tidal flat (Namhae-po in Taean). We measured the physiochemical parameters (temperature, salanity, pH, dissolved oxygen and nutrients) and the geochemical characteristics (chemical oxygen demand, ignition loss, C/N ratio and C/S ratio). Surface sediments were collected from several site of tidal flat to examine the geochemical characteristics of both the benthic environment and heavy metal pollution. The grain size for research area of tidal flat were similar at the ratio of silt and clay in comparison with the other site of it. The C/N ratio was more than 5.0, reflecting the range arising from the mix of marine organism and organic matter. The C/S ratio (about 2.8) showed that survey area had anoxic or sub-anoxic bottom conditions. The enrichment factor (Ef) and index of accumulation rate (Igeo) of the metals showed that those research areas can be classified as heavily polluted, heavily to moderately polluted, or more or less unpolluted, respectively. Adult surf clam (Mactra veneriformis) density was highest at St. 2 (middle part of the Namhae-po), on the other hand, surf clam spat density was highest at St. 3 (lower part of the Namhae-po). Heavy rain, terrigenous suspended clay with fresh water from neighboring agricultural land, and severe high air temperature during summer could be thought as detrimental causes of spat and adult mortality in Namhae-po tidal flat. We suggested that the growth of shellfish in the tidal flat was effected by the various environmental conditions, so an improvement in the cultured method was needed.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.46 no.2
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• pp.179-184
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• 2020

Elasticity and softness of the skin depend on the level of moisture present in the stratum corneum, which is known to be affected by various environmental changes, such as cold and hot winds and dry environments. However, not many studies have been conducted on changes in skin moisture and the degree of recovery due to individual skin differences. In the present study, we aimed to investigate the effect of warm air heating on skin hydration levels and develop moisturizing formulas to improve lowered skin hydration levels. In order to deliver warm air heating condition, heating dryer (40 ℃, 6 m/s, 30 cm apart from forearm) was applied into inner forearm of healthy subjects (male: 10, female: 39, age: 25 - 63) Among 49 subjects, 26 subjects showed significantly lowered skin hydration levels until 30 min after warm air heating exposure (lowered group). In addition, moisturizing cream with high water holding capacity was applied to forearm of 10 subjects in lowered group for 3 weeks and skin hydration levels after warm air heating were significantly improved at the levels of before application of warm air heating. From this study, we found out that there is a skin type that skin hydration levels are significantly decreased under warm air heating condition (dehydrated skin) and this dehydrated skin can be improved by moisturizing formulas with high water holding capacity.

• Proceedings of the Ginseng society Conference
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• 1984.09a
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• pp.13-19
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• 1984

In the previous symposium, authors reported about anti-atherogenic action of Panax ginseng, saying that red-ginseng powder increased serum HDL-cholesterol, decreased total cholesterol, TG, NEFA, in addition, decreased platelet adhesiveness. Later, Toyama group including me. reported that ginsenosides esp. $Rb_2$ enhanced HDL and decreased LDL. Also Matsuyama group and Kinki Univ. group reported that ginsenosides $Rg_1,\;Rb_2,$ etc. inhibited platelet aggregation. This paper will be divided into two parts: Experimental and clinical Experimental study; Using a highcholesterol-cholic acid-fed rats, effects of red ginseng extract and several ginsenosides on serum apoprotein-lipoproteins in relation to prostaglandins. Rats received $2\%$ cholesterol 1-1$\%$ cholic acid diet, ginseng extract or ginsenosides 2.5mg/100g/day for 9 days. Red ginseng extract, ginsenosides $Rb_2,\;Rc,\;Rb_1,\;and\;Rg_1,\;esp.\;Rb_2,$ increased HDL, apo-AI, Aii and $PGI_2,$ while they decreased LDL, apo-B and $TXA_2$. Clinical study: Effect of red ginseng powder on hyperlipidemia was observed. Long term administration of red ginseng powder manufactured by Office of Monopoly, Republic of Korea and offered by Japan-Korea Korean Ginseng Co., Kobe, at the dose of 2.7 g/day, was performed in patients with hyperlipidemia up to 4 years. The significant increase in serum HDL-cholesterol and also the significant decrease in total cholesterol, atherogenic index, TG, NEFA and lipoperoxide was observed with 3-48 month administration of red ginseng. Conclusions: Red ginseng and ginsenosides improved hyperlipidemia in rats and in man, with the improvement of blood apoproteins, lipoproteins and prostaglandins in experimental hyperlipidemic animals.

• 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.

• Clean Technology
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• v.24 no.3
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• pp.198-205
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• 2018

This study investigated the influence of catalyst preparation on the activity of $Co-CeO_2$ catalyst for $N_2O$ decomposition. $Co-CeO_2$ catalysts were synthesized by co-precipitation and incipient wetness impregnation. In order to estimate the performance of the as prepared catalysts, direct catalytic $N_2O$ decomposition test was carried out under $250{\sim}375^{\circ}C$. As a result, the catalyst prepared by co-precipitation (CoCe-CP) showed an enhanced performance on $N_2O$ decomposition reaction even in the presence of $O_2$ and/or $H_2O$, whereas the impregnation catalyst (CoCe-IM) did not. In order to investigate the difference in catalytic activity, characterization such as XRD, BET, TEM, $H_2-TPR$, $O_2-TPD$, and XPS was conducted. It is confirmed that the particle size and specific surface area were changed depending on the catalyst preparation method and the synthesis process influenced the physical properties of the catalysts. In addition, the improvement in the activity of the catalyst prepared by co-precipitation is due to the enhanced reduction from $Co^{3+}$ to $Co^{2+}$ and the improved oxygen desorption rate. However, it has been confirmed that the surface electron state and binding energy, which are related to $N_2O$ decomposition, do not change depending on the preparation method.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.11-16
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• 1976

This experiment was carried out to determine the most adequate type and period of nursery for the late seasonal cultivation of the new varieties of rice, Yusin and Josaengtongil. The results obtained are summarized as follows: 1. Semi-hot up-land nursery was much effective for the increase of the number of tillerings and the roots of rise seedlings compared with the semi-hot low-land nursery. The number of tillerings and roots was increased in 60 days seedlings compared with 50 or 60 days seedlings. 2. The abnormal heading has not appeared at the variety Yusin at all. The seedlings of Josaengtongil grown over 50 days at the semi-hot low-and nursery showed the abnormal heading, but the abnormal heading was not checked out at the seedlings of same variety grown for 60 days on the semi-hot upland nursery. 3. On the nursery not to cause the abnormal heading, earlier seeding was much effective for the hastening of the heading time and the hastening effect of heading time by earlier seeding was significantly greater at the variety Josaengtongil than Yusin 4. The number of ears per hill was significantly increased in the seedlings from the semi-hot up-land nursery compared with the semi-hot low-land nursery. 5. When the growing period of rice seedlings was not considered, the semi-hot up-land nursery resulted in higher yield of rice than the semi-hot low-land nursery. Considering the growing periods of rice seedlings, 40 days seedlings showed high yield at the semi-hot low-land nursery, however, at the semi-hot up-land nursery, 60 days seedlings showed higher yield of rice.

• Journal of dental hygiene science
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• v.1 no.1
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• pp.53-59
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• 2001

This study was aimed to survey the level of service education in the people engaging in medical services and identify the influence of the education on their job performance. This study was conducted from February 10th, 2000 to March 10th, 2000, centering on Seoul and Kyonggi area. A total of 341 questionnaires were distributed for the survey. The result ware as followings: (1) In a question about the satisfaction over general medical services such as the location of medical institutions, medical equipments and devices, and the attitudes of medical personnel, the group with service education marked 4.07 while the group with no education earned 3.97, showing statistically significant difference(p<.05). (2) In the area of medical institutions image, level of medical services and promotion, the group with service education showed 4.01 while the group with no education gained 3.83, also showing statistically significant difference(p<.05). (3) No statistically meaningful difference was revealed in the area of satisfaction for over all medical services such as the contentment about the medical services being provided, rooms for improvement and the adequacy of the number of medical personnel. The group with education acquired 3.32, with the group with no education 3.34. (4) Satisfaction about the education and awareness about medical services were high in the group of dental hygienists and showed a statistically meaningful difference. (5) The average number of education recorded 1.83 and satisfaction over service education inside the hospital was low, registering 3.24. (6) Teamwork among the personnel in the hospital was 3.70, which is relatively high. The fulfillment over given tasks posted 3.56 and the recommendation for medical institutions was low, recording 3.24. (7) The necessity of medical service education for medical personnel gained 4.40, indicating heightened awareness over the need for service education.

• Journal of dental hygiene science
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• v.15 no.2
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• pp.129-137
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• 2015

This study is conducted with the aim of providing basic data for oral health improvement of pregnant woman and development of oral health education program by analyzing factors influencing the oral health related behavior of pregnant woman applying health belief model which is theoretical model of explaining individual's behavior change. For 217 expectant mothers who visited 8 obstetrics and 1 maternity class located in Seoul, Gyeonggi and Incheon from August 1 to 31, 2014, data analysis was implemented using self-administered questionnaire. Before the completion of self-administered questionnaire, the subjects were fully informed of explanatory note and consented on taking part in the research for the consideration of ethical aspect. Collected materials were treated by PASW Statistics ver. 18.0 program and following results were acquired. Health belief factor which infuences oral health related behavior of pregnant woman resulted that perceived severity influences on oral examination during pregnancy and dental treatment during pregnancy, and perceived benefits influences on oral examination during pregnancy, and perceived barriers on toothbrushing after having a snack, toothbrush with rotation method and oral examination during pregnancy, and self-efficacy influences on use of oral hygiene products after toothbrushing and oral examination during pregnancy. With these research results, I suggest that perceived severity of health belief factor, perceived benefits, perceived barrier and self-efficacy influence oral health related behavior of pregnant woman. And specific oral health education program for pregnant woman is necessary to increase perceived severity of pregnant woman, perceived benefits and self-efficacy and to reduce perceived barriers.

• Korean Journal of Poultry Science
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• v.40 no.3
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• pp.197-205
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• 2013

This study established a method for preserving chicken primordial germ cells (PGCs) that enables long-term storage in liquid nitrogen ($LN_2$) for preservation of the species. The purpose of this study was to compare the effects of Ethylene Glycol (EG) and Propylene Glycol (PG) on viability of cryopreserved PGCs with vitrification in Korean Native Chicken (Ogye), and to fine should be find or to the optimal protocol for PGCs freezing. One of the important components of cryopreservation process is cryopreservation medium that plays a vital role in preventing cellular injury during freeze-thawing. Cryoprotective agents have been known to improve cell viability after freeze-thawing. PGCs obtained from the germinal gonade of 5.5~6 day (stage 28) chick embryos, using the MACS method were suspended in a freezing medium containing a freezing and protecting agents. Gonads were harvested from stage 28 chick embryos and pooled in groups of 10E embryos, contributing gonads to the cell suspension. The gonadal cells, including PGCs, were then frozen in 1 of the following cryoprotectant treatments: 2.5% EG, 5% EG, 10% EG, 2.5% PG, 5% PG, 10% PG, and 0% cryoprotectant as a control. Effects of exposure to vitrification solution and vitrification, with different concentrations of the cryoprotectant solution, were examined. After freezing and thawing, survival rates of the frozen-thawed PGCs from the 0, 2.5, 5, 10 and 15% EG plus FBS treatment were 44.24%, 64.51%, 85.63%, 80.51% and 73.52% (p<0.05), respectively. The viability of PGCs after freeze-thawing was significantly higher for 10% EG plus FBS treatment than for 10% PG + FBS treatment (p<0.05)(85.63% vs 66.81%). Therefore, these systems may contribute in the improvement of cryopreservation for a scarce species in birds preservation. This study established a method for preserving chicken PGC that enables systematic storage and labeling of cryopreserved PGCs in liquid N at a germplasm repository and ease of entry into a database. In the future, the importance for this new technology is that poultry lines can be conserved while work is being conducted on improving the production of germline chimeras.