• The Journal of Advanced Prosthodontics
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• v.5 no.4
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• pp.479-484
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• 2013

PURPOSE. The aim of this study was to evaluate the effects of additional acid etching and curing mechanism (light-curing or self-curing) of a composite resin on the dentin bond strength and compatibility of one-step self-etching adhesives. MATERIALS AND METHODS. Sixteen human permanent molars were randomly divided into eight groups according to the adhesives used (All-Bond Universal: ABU, Clearfil S3 Bond: CS3), additional acid etching (additional acid etching performed: EO, no additional acid etching performed: EX), and composite resins (Filtek Z-250: Z250, Clearfil FII New Bond: CFNB). Group 1: ABU-EO-Z250, Group 2: ABU-EO-CFNB, Group 3: ABU-EX-Z250, Group 4: ABU-EX-CFNB, Group 5: CS3-EO-Z250, Group 6: CS3-EO-CFNB, Group 7: CS3-EX-Z250, Group 8: CS3-EX-CFNB. After bonding procedures, composite resins were built up on dentin surfaces. After 24-hour water storage, the teeth were sectioned to make 10 specimens for each group. The microtensile bond strength test was performed using a microtensile testing machine. The failure mode of the fractured specimens was examined by means of an optical microscope at ${\times}20$ magnification. The data was analyzed using a one-way ANOVA and Scheffe's post-hoc test (${\alpha}$=.05). RESULTS. Additional etching groups showed significantly higher values than the no additional etching group when using All-Bond Universal. The light-cured composite resin groups showed significantly higher values than the self-cured composite resin groups in the Clearfil S3 Bond. CONCLUSION. The additional acid etching is beneficial for the dentin bond strength when using low acidic one-step self-etch adhesives, and low acidic one-step self-etch adhesives are compatible with self-cured composite resin. The acidity of the one-step self-etch adhesives is an influencing factor in terms of the dentin bonding strength and incompatibility with a self-cured composite resin.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.5 no.1
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• pp.123-132
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• 1985

The flexibility of base material gives considerable influences on seismic responses of a structure. The effects of relative stiffness between super-structure and base material on dynamic soil-structure interaction are evaluated by parametric studies. Two 5-story buildings are used for the study; one is shearwall structure with relatively higher fundamental frequency and the other is frame structure with relatively lower fundamental frequency. The structures are modeled as beam-sticks coupled with springs and dashpots representing the base material. Dynamic equilibrium equations of the soil-structure interaction system are sloved by mode superposition method using Rosset modal damping values. Soil-structure interaction effect is found to be major concern in seismic analysis of shearwall structure in most cases while it seldom becomes engineering problem in frame-type structure. It is also found that seismic responses at lower elevation of the super-structure are amplified though they decrease at higher elevation as soil-structure interaction effects of the system increase.

• Animal Bioscience
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• v.34 no.6
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• pp.1070-1077
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• 2021

Objective: An experiment was conducted to determine the appropriate fasting time prior to slaughter for broilers in floor-feed and scatter-feed mode. Methods: On 21 d since hatching, 120 Arbor Acres broilers were divided into floor-feed and scatter-feed groups, chicks from each group were further assigned to feed withdrawal treatments for 0, 4, 6, 8, and 10 h. Some resultant indicators such as carcass contamination, body weight loss, meat quality of 54-day-old broilers were measured. Results: It appears that longer feed withdrawal increased weight loss, lightness, drop loss of meat but reduced pH. A significant higher weight loss and lightness for both floor-feed and scatter-feed chicks coincided after 6 to 10 h feed withdrawal (p<0.05). pH for breast muscle at 45 min postmortem reduced when chicks of scatter-feed were fasted 6 and 10 h, while the reduction of floor-feed group occurred only in 10 h (p<0.05). A noticeable effect of feed withdrawal on drop loss occurred after 10 h fasting in scatter-feed of which drop loss were significantly higher than that for other groups including control (p<0.05). The change of contamination propensity revealed that 6 to 10 h fasting significantly reduced the likelihood of carcass contamination under both floor-feed and scatter-feed (p<0.05). Net weights of intestinal contents for gizzard were significantly reduced after feed deprived for 10 h in floor-feed and 6 and 10 h in scatter-feed (p<0.05). The decrease for whole intestine occurred after floor-feed broilers have been without feed for more than 4 h, scatter-feed broilers for more than 8 h (p<0.05). Conclusion: On the premise that poultry product properties and welfare were not significantly damaged, proper fasting time could reduce carcass contamination. Current data implied that 6 h fasting was recommendable for both floor and scatter feed pre-slaughter broilers.

• Journal of the korean academy of Pediatric Dentistry
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• v.46 no.2
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• pp.158-164
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• 2019

The purpose of this study was to compare the bond strength of resin-modified glass ionomer (RMGI) to dentin with saliva contamination at different stages and using different decontamination procedures. Extracted human permanent molars were embedded onto acrylic resin with the dentin surface exposed. Group I was a control group that was conditioned with polyacrylic acid (PAA). Groups II and III were contaminated with saliva before PAA conditioning and Groups IV, V, and VI were contaminated with saliva after PAA conditioning. After saliva contamination, Groups II and IV were dried, Groups III and V were rinsed and dried, and Group VI was additionally conditioned with PAA. After surface treatment, the dentin specimens were filled with RMGI. Group I showed significantly higher bond strength than the other groups. Group VI showed a significantly higher bond strength than the other saliva contaminated groups. However, there were no significant differences in the failure mode between the different groups. Saliva contamination impaired the bond strength of RMGI to dentin, regardless of when the saliva contamination occurred. Decontamination with washing and drying could not improve the shear bond strength of RMGIC. When saliva contamination occurred after PAA conditioning, additional PAA conditioning improved the shear bond strength.

• Composites Research
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• v.37 no.5
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• pp.386-392
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• 2024

Stitching is one of the techniques used to improve the through-thickness properties of CFRPs. In this study, the enhancement of CFRP properties through stitching for aerospace applications was investigated with considering high-temperature conditions and thickness effect. Stitched CFRPs were observed to have 18.2% higher maximum loads and 33.2% higher elastic moduli than non-stitched CFRPs. In addition, as the areas exposed to high temperatures increased, the mechanical properties of the CFRPs decreased regardless of stitching. In thick CFRPs, the load drop rate was complemented by stitching yarn. However, for thin CFRPs, there was no significant change in load drop rate. Additionally, it was observed from testing of the thin CFRPs that multi-layer delamination occurred as the precrack propagation direction changed due to stitching yarns. This study highlights the influence of various factors that need to be considered for the application of CFRPs in the aerospace field, and suggests improving weaknesses by enhancing mechanical properties through stitching. Finally, new perspectives on temperature conditions are presented.

• Journal of the Korea Society of Computer and Information
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• v.25 no.6
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• pp.239-250
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• 2020

The purpose of this paper is to explore the influence of the "contextualization" effect of web celebrity live broadcast on the e-commerce platform on consumers' perception of product value, risk and purchase intention. Live in this paper, using Taobao shopping consumers as the research object, the survey method, questionnaire survey is adopted, the form through the questionnaire and distributed network, a live in order to further validation of web celebrity effect of contextualized actual influence on consumer purchase intention, questionnaire design the Likert scale, seven and recycling questionnaire analysis using the statistical software SPSS 23.0 and AMOS 22.0 after processing the data. After determining the reliability and validity of the questionnaire, the exploratory factor analysis was used to verify the hypothesis and calculate the actual adjustment degree of the "contextualization" effect of web celebrity live broadcasting on consumers' purchase intention. The research results of this paper are summarized as follows :(1) consumers' perceived value of products can significantly positively affect their purchase intention, while perceived risk has a significantly negative impact on their purchase intention; (2) consumers' trust and purchase intention to products are regulated by the "contextualization" of web celebrity live broadcast. Specifically, for web celebrity live broadcasting with good "contextualization" effect, the perceived value of consumer products has a positive impact on product trust, which is higher than that of web celebrity live broadcasting with poor "contextualization" effect. In terms of resolving consumers' perceived risks to products, web celebrity live broadcast with good "contextualization" effect is also significantly better than web celebrity live broadcast with poor "contextualization" effect. Based on empirical analysis, this paper concludes that web celebrity live broadcasting will become a new breakthrough for the sustainable growth of the e-commerce industry, and puts forward Suggestions on the e-commerce marketing mode and the transformation of web celebrity live broadcasting industry.

• Restorative Dentistry and Endodontics
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• v.33 no.3
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• pp.169-176
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• 2008

The purpose of this study was to evaluate the effect of thickness, filling methods and curing methods on the polymerization of dual cured core materials by means of microhardness test. Two dual cured core materials, MultiCore Flow (Ivoclar Vivadent AG, Schaan, Liechtenstein) and Bis-Core (Bisco Inc., Schaumburg, IL, USA) were used in this study. 2 mm (bulky filled), 4 mm (bulky filled), 6 mm (bulky and incrementally filled) and 8 mm (bulky and incrementally filled)-thickness specimens were prepared with light cure or self cure mode. After storage at $37{\circ}C$ for 24 hours, the Knoop hardness values (KHN) of top and bottom surfaces were measured and the microhardness ratio of top and bottom surfaces was calculated. The data were analyzed using one-way ANOVA and Scheffe multiple comparison test, with ${\alpha}$= 0.05. The effect of thickness on the polymerization of dual cured composites showed material specific results. In 2, 4 and 6 mm groups, the KHN of two materials were not affected by thickness. However, in 8 mm group of MultiCore Flow, the KHN of the bottom surface was lower than those of other groups (p < 0.05). The effect of filling methods on the polymerization of dual cured composites was different by their thickness or materials. In 6 mm thickness, there was no significant difference between bulk and incremental filling groups. In 8 mm thickness, Bis-Core showed no significant difference between groups. However, in MultiCore Flow, the microhardness ratio of bulk filling group was lower than that of incremental filling group (p < 0.05). The effect of curing methods on the polymerization of dual cured composites showed material specific results. In Bis-Core, the KHN of dual cured group were higher than those of self cured group at both surfaces (p < 0.05). However, in MultiCore Flow, the results were not similar at both surfaces. At the top surface, dual cured group showed higher KHN than that of self cured group (p < 0.05). However, in the bottom surface, dual cured group showed lower value than that of self cured group (p < 0.05).

• Proceedings of the KACD Conference
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• 2008.05a
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• pp.169-176
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• 2008

The purpose of this study was to evaluate the effect of thickness, filling methods and curing methods on the polymerization of dual cured core materials by means of microhardness test. Two dual cured core materials, MultiCore Flow (Ivoclar Vivadent AG, Schaan, Liechtenstein) and Bis-Core (Bisco Inc., Schaumburg, IL, USA) were used in this study. 2 mm (bulky filled), 4 mm (bulky filled), 6 mm (bulky and incrementally filled) and 8 mm (bulky and incrementally filled)-thickness specimens were prepared with light cure or self cure mode. After storage at $37^{\circ}C$ for 24 hours, the Knoop hardness values (KHN) of top and bottom surfaces were measured and the microhardness ratio of top and bottom surfaces was calculated. The data were analyzed using one-way ANOVA and Scheffe multiple comparison test, with ${\alpha}=0.05$. The effect of thickness on the polymerization of dual cured composites showed material specific results. In 2, 4 and 6 mm groups, the KHN of two materials were not affected by thickness. However, in 8 mm group of MultiCore Flow, the KHN of the bottom surface was lower than those of other groups (p < 0.05). The effect of filling methods on the polymerization of dual cured composites was different by their thickness or materials. In 6 mm thickness, there was no significant difference between bulk and incremental filling groups. In 8 mm thickness, Bis-Core showed no significant difference between groups. However, in MultiCore Flow, the microhardness ratio of bulk filling group was lower than that of incremental filling group (p < 0.05). The effect of curing methods on the polymerization of dual cured composites showed material specific results. In Bis-Core, the KHN of dual cured group were higher than those of self cured group at both surfaces (p < 0.05). However, in MultiCore Flow, the results were not similar at both surfaces. At the top surface, dual cured group showed higher KHN than that of self cured group (p < 0.05). However, in the bottom surface, dual cured group showed lower value than that of self cured group (p < 0.05).

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.4
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• pp.2277-2282
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• 2013

Purpose: Mammography has been confirmed as the only effective mode to improve the prognosis of patients with breast cancer in Western developed countries, but might not be a good choice in other areas of the world. One of the major challenges in China is to determine an optimal imaging modality for breast cancer screening. This study was designed to clarify the sensitivity of ultrasonography compared with that of mammography in rural China. Methods: We retrospectively studied the sensitivity of mammography and ultrasonography based on 306 breast cancer patients detected by the program of "screening for cervical cancer and breast cancer" performed in Chinese rural areas between January 2009 and December 2011, and analyzed the effects of age, breast density and volume on the sensitivity. Results: Stratified analysis showed that the sensitivity of breast ultrasonography was significantly higher than that of mammography in premenopausal patients (81.4% vs. 61.1%, p=0.02), in women ${\leq}$ 55 years of age (82.2% vs. 63.4%, p<0.01), in the high breast density group (American College of Radiology [ACR] levels 3-4) (85.9% vs. 60.6%, p<0.01) and in the small breast volume group (${\leq}$ 400 ml) (87.1% vs. 66.7%, p<0.01). Age had a significant effect on sensitivity of mammography (breast density and volume-adjusted odds ratio, 6.39; 95% confidence interval, 2.8-14.4 in age group > 55 compared to age group ${\leq}$ 45), but not that of ultrasonography. Neither breast density nor volume had significant effect on sensitivity of mammography or ultrasonography. Conclusions: Ultrasonography is more sensitive than mammography in detecting breast cancer in women under 55 year-old Chinese, especially in those with high-density and relatively small breasts.

• Korean Journal of Pharmacognosy
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• v.25 no.3
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• pp.238-248
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• 1994

The hypoglycemic and metabolic effects of Commelina communis L. extract were investigated in alloxan induced diabetic rats. The increased blood glucose level in the diabetic rats was significantly reduced and the loss of body weight was recovered with the treatment of the plant protein fractions($30{\sim}70%$ ammonium sulfate precipitates). Administration of the plant protein fractions elicited the significant increase of glucose-6-phosphate dehydrogenase (G-6-P DH) activity and liver weight which were decreased in the diabetic rat liver. G-6-P DH was partially purified from extract- or insulin-treated diabetics, diabetic control, and normal rat liver and studied for the biochemical properties. The $K_m$ value(9.002 mM) of diabetic rat liver enzyme was greatly higher than that (0.033 mM) of normal enzyme indicating the affinity of enzyme for the substrate was significantly reduced in the diabetic rat liver. This reduced affinity of enzyme for the substrate in the diabetic rat was recovered in the extract- or insulin-treated rat liver enzyme having 0.164 or 0.208 mM of their $K_m$ values, respectively. Although there was no significant difference in the optimum pH(6.0) and optimum temperature($37^{\circ}C$) of enzyme among the experimental groups, the dependence of their activities on pH appeared to be slightly resistant in the extract- or insulin-treated group compared to the diabetic group. In order to investigate the antigenicity of rat liver enzyme among experimental groups, enzyme-linked immunosorbent assay was carried out by using anti-G-6-P DH anti-serum. Absorbance(0.102) shown in the normal rat liver was reduced even below zero in the alloxan-diabetic rat liver, but increased again in the extract- or insulin-treated rat liver(0.096 or 0.118, respectively). The result of this study suggested that G-6-P DH may be used as a marker enzyme to diagnose and to indicate the progress of the diabetics, and the hypoglycemic effect of the extracts of Commelina communis L. was certainly associated with action or mode of G-6-P DH on the rat liver.