• Journal of Dental Rehabilitation and Applied Science
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• v.23 no.3
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• pp.249-257
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• 2007

State of problem : The use of zirconium oxide all-ceramic material provides several advantages, including a high flexural strength(>1000MPa) and desirable optical properties, such as shading adaptation to the basic shades and a reduction in the layer thickness. Along with the strength of the materials, the cementation technique is also important to the clinical success of a restoration. Nevertheless, little information is available on the effect of different surface treatments on the bonding of zirconium high-crystalline ceramics and resin luting agents. Purpose : The aim of this study was to test the effects of surface treatments of zirconium on shear bond strengths between bovine teeth and a zirconia ceramic and evaluate differences among cements Material and methods : 54 sound bovine teeth extracted within a 1 months, were used. They were frozen in distilled water. These were rinsed by tap water to confirm that no granulation tissues have left. These were kept refrigerated at $4^{\circ}C$ until tested. Each tooth was placed horizontally at a plastic cylinder (diameter 20mm), and embedded in epoxy resin. Teeth were sectioned with diamond burs to expose dentin and grinded with #600 silicon carbide paper. To make sure there was no enamel left, each was observed under an optical microscope. 54 prefabricated zirconium oxide ceramic copings(Lava, 3M ESPE, USA) were assigned into 3 groups ; control, airborne-abraded with $110{\mu}m$ $Al_2O_3$ and scratched with diamond burs at 4 directions. They were cemented with a seating force of 10 ㎏ per tooth, using resin luting cement(Panavia $F^{(R)}$), resin cement(Superbond $C&B^{(R)}$), and resin modified GI cement(Rely X $Luting^{(R)}$). Those were thermocycled at $5^{\circ}C$ and $55^{\circ}C$ for 5000 cycles with a 30 second dwell time, and then shear bond strength was determined in a universal test machine(Model 4200, Instron Co., Canton, USA). The crosshead speed was 1 mm/min. The result was analyzed with one-way analysis of variance(ANOVA) and the Tukey test at a significance level of P<0.05. Results : Superbond $C&B^{(R)}$ at scratching with diamond burs showed the highest shear bond strength than others (p<.05). For Panavia $F^{(R)}$, groups of scratching and sandblasting showed significantly higher shear bond strength than control group(p<.05). For Rely X $Luting^{(R)}$, only between scratching & control group, significantly different shear bond strength was observed(p<.05). Conclusion : Within the limitation of this study, Superbond $C&B^{(R)}$ showed clinically acceptable shear bond between bovine teeth & zirconia ceramics regardless of surface treatments. For the surface treatment, scratching increased shear bond strength. Increase of shear bond strength by sandblasting with $110{\mu}m$ $Al_2O_3$ was not statistically different.

• Tuberculosis and Respiratory Diseases
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• v.47 no.2
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• pp.172-183
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• 1999

Background: Nitric oxide is a short-lived effector molecule derived from L-arginine by the nitric oxide synthase(NOS). Nitric oxide plays a role in a number of physiologic and pathophysiologic functions including host defense, edema formation, and regulation of smooth muscle tone. Some kinds of cells including macrophage are known to produce large quantities of nitric oxide in response to inflammatory stimuli such as interleukin-$1\beta$(IL-$1\beta$), tumor necrosis factor-$\alpha$(TNF-$\alpha$), interferon-$\gamma$(IFN-$\gamma$) and lipopolysaccharide(LPS). Reactive oxygen species are also known to be important in the pathogenesis of acute cell and tissue injury such as acute lung injury model Methods: Using the RA W264.7 cells, we have examined the ability of oxidant hydrogen peroxide($H_2O_2$) to stimulate nitric oxide production and inducible NOS mRNA expression. Also, we have examined the effects of NOS inhibitors and antioxidants on $H_2O_2$ induced nitric oxide production. Results: Stimulation of RAW264.7 cells with combinations of 100 ng/ml IL-$1\beta$, 100 ng/ml TNF-$\alpha$, and 100 U/ml IFN-$\gamma$ or 100 U/ml IFN-$\gamma$ and $1{\mu}g/ml$ LPS induced the synthesis of nitric oxide as measured by the oxidation products nitrite($NO_2^-$) and nitrate($NO_3^-$). Addition of $250 {\mu}M-2$ mM $H_2O_2$ to the cytokines significantly augmented the synthesis of $NO_2^-$ and $NO_3^-$(p<0.05). When cells were incubated with increasing concentrations of $H_2O_2$ in the presence of IL-$1\beta$, TNF-$\alpha$ and IFN-$\gamma$ at constant level, the synthesis of $NO_2^-$ and $NO_3^-$ was dose-dependently increased(p<0.05). $N^G$-nitro-L-arginine methyl ester(L-NAME), dose dependently, significantly inhibited the formation of $NO_2^-$ and $NO_3^-$ in cells stimulated with LPS, IFN-$\gamma$ and $H_2O_2$ at constant level(p<0.05). Catalase significantly inhibited the $H_2O_2$-induced augmentation of cytokine-induced $NO_2^-$ and $NO_3^-$ formation(p<0.05). But, boiled catalase did not produce a significant inhibition in comparison with the native enzyme. Another antioxidant 2-mercaptoethanol and orthophenanthroline dose-dependently suppressed $NO_2^-$ and $NO_3^-$ synthesis(p<0.05). Northern blotting demonstrated that H:02 synergistically stimulated the cytokine-induced iNOS mRNA expression in RA W264.7. Conclusion: These results suggest that $H_2O_2$ contributes to inflammatory process by augmenting the iNOS expression and nitric oxide synthesis induced by cytokines.

• Tuberculosis and Respiratory Diseases
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• v.54 no.2
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• pp.210-218
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• 2003

Background : Sex specific cross sectional reference values for the lung function indices usually employ a linear model with a term for age and height. The purpose of this study was to determine the effects of the body mass index (BMI), the fat percentage of the body mass and the fat-free mass index (FFMI) on the forced expiratory volume curve. Methods : Between January 2000 and December 2001, a total of 300 subjects, 150 men and 150 women (mean age : $45{\pm}13$ years), with a normal lung function were enrolled in the study sample. This study measured the $FEV_1$, FVC and $FEF_{25-75%}$ from the forced expiratory volume curve by a spirometer and the body composition by a bioelectrical impedance method in all subjects. Multiple regression analysis was used in order to examine the effects of the body composition on the parameters derived from the forced expiratory volume curve. Results : After adjusting for age, the BMI and Fat percentage improved the descriptions of the FVC (p<0.05, $r^2=0.491$) and $FEV_1$ (p<0.05, $r^2=0.654$) in women. In contrast, the FFMI contributed significantly to the FVC (p<0.05, $r^2=0.432$) and $FEV_1$ (p<0.05, $r^2=0.567$) in men. The $FEF_{25-75%}$ correlated with the fat percentage in women (p<0.05, $r^2=0.337$). Conclusion : These results suggest that the BMI, the fat percentage and the FFMI are significant determinants of the forced expiratory volume curve. The plmonary function test, when considering the BMI, the fat percentage and the FFMI, might be useful in clinical applications.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.26 no.1
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• pp.135-170
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• 2015

This study aimed to investigate the transition of academic libraries' jobs by developing a model based on a shift of library generations including Library 1.0, Library 2.0, and Library 3.0 corresponding to the shift of web generations and to explore generational characteristics of library duties as well. The research used three phases of procedure: literature review about different library generations; job analyses for academic libraries in South Korea and the U.S.A.; the Delphi technique in tree sequential order. The research findings were as follows. First of all, there were 170 duties that continued from Library 1.0 to Library 3.0. There were 58 duties which continued from Library 2.0 to Library 3.0 whereas three duties that continued from Library 1.0 to Library 2.0. In addition, three distinctive duties existed only in Library 1.0 whereas one unique duty was only in Library 2.0. Library 3.0 generated 25 new duties. Secondly, considering general characteristics which cover specific parts of individual duties, there was a significant increase in importance, difficulty, and frequency of library administration throughout the three generations. In terms of importance, difficulty, and frequency of collection development and management, there was a significant increase only from Library 2.0 to Library 3.0. Considering information organization, there was a significant decrease in importance from Library 1.0 to Library 2.0. In addition, there was a significant decrease in frequency and there was no significant difference in difficulty throughout the three generations. In the case of information service, while there was a significant increase in importance among three generations, there was a significant increase in difficulty only from Library 1.0 to Library 2.0. However, there was no generational difference in frequency. With the respect of information system development and management, there was a significant increase in importance and frequency throughout the three generations, but there was no significant difference in difficulty among three generations.

• Journal of Gastric Cancer
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• v.9 no.4
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• pp.246-255
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• 2009

Purpose: The objectives of this study were to investigate the impact of the number of resected lymph nodes on the survival of gastric cancer patients who underwent curative resection, and to evaluate the cut-off values that can have an influence on survival on the tumor stage-stratified analysis. Materials and Methods: The subjects were 949 gastric cancer patients who underwent curative resection at Korea University Medical Center from 1992 to 2002. They were classified according to the depth of tumor invasion, and the influence of the number of resected lymph nodes on survival was investigated. The cut-off value for the number of resected lymph nodes was determined as the smallest value that showed a significant survival difference. Results: The tumor size, location, lymph node stage, the number of metastatic lymph nodes and the number of resected lymph nodes were significantly different according to the tumor stage. The average number of resected lymph nodes was about 39, and it showed linear correlation with the number of metastatic lymph nodes. On the Cox proportional hazard model, the cut-off values of the number of resected lymph nodes, as corrected by the number of metastatic lymph nodes, was 14 for all the patients, 15 for the pT1 patients, 28 for the pT2 patients and 37 for the pT3 patients, respectively. Conclusion: Retrieving a number of lymph nodes that is more than the cut-off value could improve the survival of gastric cancer patients. Surgeons should also make efforts to perform an exact and thorough D2 lymph node dissection. Therefore, we urge surgeons to perform D2 dissection and pathologists should examine an certain exact number of lymph nodes.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.7
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• pp.1071-1076
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• 2016

The feasibility of incorporating aronia powder (AP) as a value-added food ingredient into convenient food products was investigated using cookie as a model system. AP was incorporated into cookies at amounts of 0, 1, 2, 3, and 4% (w/w) based on total weight of wheat flour. The pH level of cookie dough decreased significantly with increasing levels of AP (P<0.05), whereas moisture content and density were not directly affected by levels of AP incorporation. The spread ratio increased significantly upon addition of AP; however, it was not significantly affected by level of AP incorporation. The loss rate of cookies decreased significantly with increasing levels of AP (P<0.05). In terms of color, lightness and yellowness decreased while redness increased significantly (P<0.05) with increasing levels of AP. Use of AP significantly decreased hardness of cookies (P<0.05), but no significant differences were found between control and 1% sample, 1% and 2% sample, 2% and 3% sample, and 3% and 4% sample (P>0.05). 2,2-Diphenyl-1-picrylhydrazyl (DPPH) and 2,2'-azino-bis-3-ethylbenzthiazoline-6-sulphonic acid (ABTS) radical scavenging activities were significantly elevated by AP addition, and they increased significantly as AP concentration increased in the formulation (P<0.05). Correlation analysis indicated that acceptances of color and chewiness were negatively correlated well with the level of AP incorporation, density and moisture content of cookie dough, and cookie redness, whereas they were positively correlated with pH of cookie dough, loss rate, and hardness (P<0.01 or P<0.05). Finally, consumer acceptance test indicated that the highest levels of AP incorporation (4%) had an adverse effect on general consumer preferences. In contrast, cookies with moderate levels of AP (2%) are recommended based on overall scores to take advantage of the antioxidant properties of AP without sacrificing consumer acceptability.

• Journal of Global Scholars of Marketing Science
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• v.19 no.2
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• pp.27-39
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• 2009

Compulsive consumption is regarded as a global phenomenon that can adversely affect consumer well-being. Although the topic has been studied in different cultural settings, we have seen relatively little theory development and explanations of compulsive behavior Nearly all previous empirical studies attempt to explain this behavior by correlating measures of compulsive behavior with independent variables taken within the same time frame. However, recent developments in social sciences suggest that such a phenomenon may best understood in the context of the person's earlier-in-life experiences. Using the life course paradigm as an overarching framework, the present research extends previous work on this topic. Following hypotheses were drawn from literature review: H1: The earlier in childhood and adolescence a person experiences family dislocation, the greater his or her likelihood of exhibiting compulsive behaviors in adulthood. H2: The earlier in life the young person experienced family dislocation, the greater the number of family disruption events the young person experienced prior entering adulthood years. H3: Family dislocation leads to (a) increased frequency of socio.oriented family communications and (b) decreased frequency of concept-oriented family communication. H4: Young adults who were raised in families characterized by a strong socio-oriented communication structure are more likely to exhibit compulsive consumption tendencies than those who were raised in families characterized by a weak socio-oriented family communication structure. H5: Young adults who were raised in families characterized by a strong concept-oriented communication structure are less likely to exhibit compulsive consumption tendencies than those who were raised in families characterized by a week concept-oriented family communication structure. H6: The relationship between family disruption events experienced during adolescence and perceived stressfulness of these events is moderated by (a) global family support, (b) emotional family support, and (c) material family support. Those reporting higher levels of family support as teenagers are less likely to report experiencing stress due to family disruption events. H7: Perceived stressfulness of family disruption events experienced during adolescent years are associated with compulsive consumption tendencies in early adulthood. H8: The greater the number of family disruption events young adults experienced during their adolescent years the more frequent was their communication about consumption with their peers. H9: The more frequent was the young persons' communication with their peers about consumption during their adolescent years, the more likely they are to report compulsive buying tendencies as young adults. We use a sample of 120 Thai undergraduate students attending classes taught in English as part of a four-year international program. Product-moment correlations, hierarchical regression analysis and partial correlation were used to analyze data. Results of testing hypotheses showed that hypothesis 2, 4, 7 and 9 were supported and hypothesis 1, 3, 5, 6 and 8 were not supported. Our study did not find a significant relationship between the age when a person experienced family dislocation and their compulsive behavior tendencies expressed as young adults. We did not find a significant relationship between family dislocation and family communication structures. But we found a significant positive relationship between socio-oriented communication structure and compulsive buying and a significant relationship between our peer communication and compulsive buying measures. Also we found perceived stressfulness due to the disruptive events to have a significant positive relationship between the perceived stressfulness and compulsive buying. Implications from these findings, limitations of this research and future research suggestions were discussed.

• Journal of Korean Academy of Nursing
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• v.30 no.1
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• pp.122-136
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• 2000

Chronic illness requiring attention and management during a long period of time puts great burden onto patients, their family and society. For patients with chronic illnesses, providing social support is the most important, and the fundamental support comes from their spouses. Amount and quality of support from spouses seems to differentiated according to the sex of patients. Female patients tend to believe that their spouses are not very supportive. Therefore, the researchers assessed the burden of husbands of female arthritis patients to discover the factors that result in greater burden. Also, they developed a theoretical model of husbands′ care for their wives through a qualitative research into husbands′ experience. Method 1: The study material was 650 female arthritis patients registered in an arthritis clinic. The questionnaire about the disease experience of female arthritis patients and the burden of husbands were sent. Returned questionnaires numbered 210(32.3%) and 27 were excluded because of inadequate answers. The remaining 183 questionnaires were analyzed. The mean age of the patients was 51 years and the mean age of spouses was 55 years. The mean marital period was 28 years. The average duration since diagnosis was 9.1 years. Education level was varied from primary school to graduate school, and average income/month was 1,517,300 won. Method 2: Initial questionnaire studies on the burden of husbands were performed. Among 183 responding husbands, 23 consented to participate for a qualitative research. Data was obtained by direct and telephone interviews. The mean age of participants was 58 years, and the educational level and socioeconomic status also varied. Result: 1. Husbands′ burden: The average burden was 57.68 with a range of 6-96. 2. Burden and general characteristics: The husband′s burden correlated with the age of the patients, numbers in the family, therapy methods, patient′s level of discomfort, patient′s disease severity, patient′s level of dependence and the husband′s understanding of the level of severity. 3. Linear correlation analysis on burden: The husbands′ burden is explained in 22.5% by husband′s recognition of level of severity and husbands′ age. 4. There were four patterns of the burden on husbands: both objectve burden and subjective burden were high(pattern I), both of objectve burden and subjective burden were low(pattern II), objective burden was high but subjective burden was low(pattern III), objective burden was low but subjective burden was high(pattern IV). The pattern was correlated with the family income, educational level of the patients and their husbands, therapy methods, patient′s level of discomfort, patient′s disease severity, patient′s level of dependence and husband′s understanding of level of severity. 5. The core category of the caring experience of the husbands with arthritis patients was "companionship". The causal factor was the patients′ experience due to symptoms : physical disfigurement, pain, immobility, limitation of house chores, and limitation of social activities. Contextural factors are husbands′ identification of housework and husbands′ concern about the disease. The mediating factors are economic problems, fear of aging, feeling of limitation and family support. The strategy for interaction is mind control and how to solve emotional stress. The "companionship" resulted from caring activities, participation of household activities, helping patients′ to coping with emotional experience. 6. Companionship is established through the process of entering intervention, and caring state of mind. Entering intervention is the phase of participation of therapy and involvement of houseworks. The caring phase consists of decision on therapy, providing therapy, providing direct care, and taking over the household role of wife. Through caring phase, the changing phase set a stage in which husbands consolidate the relationship with their wives, and are reminded of the meaning of marriage. As a result, in changing phase, husbands′ companionship is enhanced. In conclusion, nursing care of chronic illnesses should include a family member especially the spouse. All information on disease shoud be provided to patients and whole family member. Strong support should also be provided to overcome difficulties in taking over role of other sex. Then the quality of life of patients and families will be much improved.

• The korean journal of orthodontics
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• v.35 no.6 s.113
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• pp.475-484
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• 2005

This study was performed to investigate the reproducibility of the horizontal and midsagittal planes, and to suggest a stable coordinate system for three-dimensional (3D) cephalometric analysis. Eighteen CT scans were taken and the coordinate system was established using 7 reference points marked by a volume model, with no more than 4 points on the same plane. The 3D landmarks were selected on V works (Cybermed Inc., Seoul, Korea), then exported to V surgery (Cybermed Inc., Seoul, Korea) to calculate the coordinate values. All the landmarks were taken twice with a lapse of 2 weeks. The horizontal and midsagittal planes were constructed and its reproducibility was evaluated. There was no significant difference in the reproducibility of the horizontal reference planes, But, FH planes were more reproducible than other horizontal planes. FH planes showed no difference between the planes constructed with 3 out of 4 points. The angle of intersection made by 2 FH planes, composed of both Po and one Or showed less than $1^{\circ}$ difference. This was identical when 2 FH planes were composed of both Or and one Po. But, the latter cases showed a significantly smaller error. The reproducibility of the midsagittal plane was reliable with an error range of 0.61 to $1.93^{\circ}$ except for 5 establishments (FMS-Nc, Na-Rh, Na-ANS, Rh-ANS, and FR-PNS). The 3D coordinate system may be constructed with 3 planes; the horizontal plane constructed by both Po and right Or; the midsagittal plane perpendicular to the horizontal plane, including the midpoint of the Foramen Spinosum and Nc; and the coronal plane perpendicular to the horizontal and midsagittal planes, including point clinoidale, or sella, or PNS.

• The korean journal of orthodontics
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• v.37 no.2 s.121
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• pp.98-113
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• 2007

Objective: The purpose of this study was to evaluate the displacement pattern and the stress distribution shown on a finite element model 3-D visualization of a dry human skull using CT during the retraction of upper anterior teeth. Methods: Experimental groups were differentiated into 8 groups according to corticotomy, anchorage (buccal: mini implant between the maxillary second premolar and first molar and second premolar reinforced with a mini Implant, palatal: mini implant between the maxillary first molar and second molar and mini implant on the midpalatal suture) and force application point (use of a power arm or not). Results: In cases where anterior teeth were retracted by a conventional T-loop arch wire, the anterior teeth tipped more postero-inferiorly and the posterior teeth moved slightly in a mesial direction. In cases where anterior teeth were retracted with corticotomy, the stress at the anterior bone segment was distributed widely and showed a smaller degree of tipping movement of the anterior teeth, but with a greater amount of displacement. In cases where anterior teeth were retracted from the buccal side with force applied to the mini implant placed between the maxillary second premolar and the first molar to the canine power arm, it showed that a smaller degree of tipping movement was generated than when force was applied to the second premolar reinforced with a mini implant from the canine bracket. In cases where anterior teeth were retracted from the palatal side with force applied to the mini implant on the midpalatal suture, it resulted in a greater degree of tipping movement than when force was applied to the mini implant between the maxillary first and second molars. Conclusion: The results of this study verifies the effects of corticotomies and the effects of controlling orthodontic force vectors during tooth movement.