• Journal of dental hygiene science
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• v.23 no.1
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• pp.29-38
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• 2023

Background: The purpose of this study was to investigate the effect of salad dressings on the flowable composite resin surface and the erosion-inhibitory effect of calcium. Methods: The experiment included six groups: oriental dressing, balsamic dressing, lemon-garlic dressing, lemon-garlic dressing supplemented with 3% calcium, mineral water as a negative control group, and orange juice as a positive control group. pH and titratable acidity were measured. The prepared specimens were immersed in the experimental solutions for 1, 3, 5, 15, and 30 minutes. The surface microhardness was measured using the Vickers hardness number before and after the treatment, and the surface of the specimens was observed using a scanning electron microscope (SEM). Results: The pH values of the experimental groups in increasing order were as follows: lemon-garlic dressing (2.49±0.03), balsamic dressing (3.12±0.06), lemon-garlic dressing +3% calcium (3.27±0.09), oriental dressing (3.75±0.03), orange juice (3.82±0.02), and mineral water (7.32±0.16). The largest surface hardness reduction value was shown in lemon-garlic dressing (-9.61±1.16), followed by balsamic dressing (-9.17±1.63), oriental dressing (-8.62±1.09), orange juice (-8.19±1.36), lemon-garlic dressing +3% calcium (-6.76±1.23), and mineral water (-1.63±2.47). According to the SEM findings, the experimental and positive control groups showed rough surfaces and micropores, whereas the negative control group showed a smooth surface. Moreover, the lemon-garlic dressing with +3% calcium showed fewer micropores and a smoother surface than the lemon-garlic dressing. Conclusion: The intake of salad dressings at a low pH could weaken the surface microhardness of the flowable composite resin. However, adding calcium to these salad dressings can reduce the risk of microhardness reduction on the flowable composite resin surface.

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.81-88
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• 2007

One hundred and forty-four cross-bred market pigs weighing approximately 110 kg were randomly divided into six groups in a 3 (duration of fasting prior to loading; 0, 12 and 24 h) ${\times}$ 2 (handling stress; minimal vs stimulated handling stress) factorial arrangement of treatments. The stimulated handling stress group received overally rough handling including electric prod stimulation during loading, transport and lairage at least once at each step. All the animals received 3-h lairage prior to slaughter. Blood and longissimus dorsi muscle (LM) samples were taken at slaughter and after overnight chilling of the carcass, respectively. Mean plasma glucose concentration, as expected, was less in the 12 h- or 24 h-fasting group than in the 0 h-fasting, whereas cortisol concentration was greater (P<0.05) in the 24 h- vs 0 h-fasting group. Plasma concentrations of stress indicators glucose, cortisol, creatine kinase and lactate dehydrogenase were greater in the stimulated vs minimal handling stress group. There were no interactions between the duration of fasting and handling stress in their effects on these blood variables. The incidence of pale, soft and exudative (PSE) carcass and drip loss of LM were reduced in the 12 h- or 24 h- vs 0 h-fasting group, whereas the 24-h postmortem LM pH and color including the lightness and redness were not affected by the duration of fasting. The incidence of PSE carcass and physicochemical characteristics of LM, however, were not changed by the stimulated vs minimal handling stress. In conclusion, results suggest that fasting the market pig overnight prior to transport is desirable in terms of reducing the incidence of PSE carcass. Rough handling of market pigs may not affect the carcass quality of the animals when an enough lairage time is provided. However, rough handling inflicts a stimulated stress on the animal, which is manifested by increased blood concentrations of stress indicators, and therefore should be avoided fer animal welfare.

• Journal of Adhesion and Interface
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• v.10 no.3
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• pp.127-133
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• 2009

Acrylic pressure sensitive adhesives (PSAs) are used in various field of high-technology industries such as semiconductor, display, mobile, automobile, and so on. Because of they have high durabilities and can be easily introduced functional groups in their molecular structures. PSA perfomances has an effect on their applications in industry process operation, reliability of final products. In this study, PSA performances as a function of fim thickness which is one of the impact factors effects on PSA performances will be investigated using combinatorial methods. Acrylic PSAs are synthesized using 2-ethylhexyl acrylate and acrylic acid. Thickness-gradient of acrylic PSA sample is made by a micro applicator. We compare general coating method with thickness-gradient coating method and evaluate the reappearance of combinatorial methods compared with existing coating method. Thickness-gradient of acrylic PSA sample shows rough and broad data tendency.

• Journal of Physiology & Pathology in Korean Medicine
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• v.22 no.6
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• pp.1378-1382
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• 2008

This study is aim to evaluate pulse diagnosis as indicators for classification of the pattern identifications in stroke patients. To get the clinical information, we recruited the onset 1 month stroke patients through the multicenter network which consists of 13 oriental hospitals. The clinical informations about three pairs of pulse wave form and levels of their significancy based on the case report form (CRF) were collected and their distribution in each pattern identification were analyzed. The results are as follows Fire-Heat group shows high portions of floating pulse, rapid pulse and solid pulse. Qi Defficiency group has a greater portion of deep pulse, slow pulse, deficient pulse. The well-defined character of Phlegm-Retained Fluid, Yin Defficiency, Static Blood groups cannot be explained by pulse wave form. These results show a rough relationship between the pulse diagnosis and pattern identifications of stroke therefore, further studies are required to determine the pulse diagnosis as significant indicators of stroke pattern identification.

• The Journal of Korean Academy of Prosthodontics
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• v.29 no.3
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• pp.87-99
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• 1991

The effect of oven firing on the color stability and surface texture of extrinsic stains used characterization and color modification of metal cermic restoration were studied by comparing different temperatures and techniques. They were autoglaze technique, applied glaze technique, two step low-fusing glaze technique and one step low-fusing glaze technique. Autoglaze technique and applied glaze technique were air-fired to manufacturer's recommended temperature. Two step low-fusing glaze technique is separated staining and overglazing. Thin slurry of stain powder were air-fired to $1500^{\circ}F$, Overglaze powder powder was then mixed with seam medium and air-fired to $170^{\circ}F$. One step low-fusing glaze technique is combined staining and overglazing. Thin slurry of stain and glaze powder were air-fired to $170^{\circ}F$. The obtained results were as fellows. 1. Slightly significant color differences by colorimeter were found between different stain application and fusion techniques(P<0.05). 2. Two step low-fusing glaze method showed the most rough surface, especially ceramco orage stain(P<0.05). 3. Surface roughness increased gradually in order of autoglaze, applied glaze, one step low-fusing glaze but they were not significantly different(P<0.05). 4. When two step low-fusing glaze was applied, both color measurement and surface texture were sinificantly different from other groups(P<0.05).

• The Journal of Korean Academy of Prosthodontics
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• v.38 no.3
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• pp.336-347
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• 2000

Statement of problem. Luster loss in esthetic anterior ceromer restoration can occur and can be related with rough surface texture. Understanding durability of surface finishing methods like polishing and surface coating have critical importance. Purpose. This study evaluated the effect of tooth brushing and thermal cycling on surface luster of 3 ceromer systems (Artglass, Targis, Sculpture) treated with different surface finishing methods. Material and methods. Seventy-two samples were prepared: 12 for control group Z100, 12 for Artglass, 24 for Targis, and 24 for Sculpture. Half of the Targis and Sculpture were polished according to the manufacturer's recommendation. The rest of the samples were coated with staining and glazing solution for Targis and Sculpture, respectively. All specimens were subjected to 10,000 cycles between $5^{\circ}C\;and\;55^{\circ}C$ with 30 seconds dwell time. Tooth brushing abrasion tests were performed in a customized tooth brushing machine with 500g back and forth for 20,000 cycle. Luster comparisons were based on grading after direct observation, and light reflection area was measured with Image analysis software. Results. All materials showed an decrease in luster grade after thermal cycling and tooth brushing. The post-tooth brushing results revealed that the glazed Sculpture had greater mean luster grade than did any other groups. While, the stained Targis group showed greatest changes after tooth brushing (p < 0.05), polished Targis and Sculpture did not show significant changes. However, glazed Sculpture showed discretely fallen out glaze resin. Conclusion. From the results of this study, all of the ceromer specimens were much glossy than control composite group after tooth brushing. coatings used for Targis and Sculpture had not durability for long term use.

• Journal of Periodontal and Implant Science
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• v.32 no.2
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• pp.303-314
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• 2002

This study was performed to evaluate the usability of Er:YAG laser for periodontal therapy. Forty dental root slabs ($5{\times}5{\times}2mm^3$) were prepared from human periodontally diseased extracted teeth and grouped into 4 groups: 1) control (root planing only), 2) root planing and irradiated with laser at 30mJ, 3) root planing and irradiated with laser at 60mJ, and 4) root planing and irradiated with laser at 100mJ. The root slabs were embedded in resin block before laser treatment. Er:YAG laser was irradiated under water irrigation with the tip held perpendicular to the root surface in contact mode. After Er:YAG laser irradiation or planing on the root surface, morphological changes have been observed under SEM, and the micro-hardness and Ca/P ratio were compared. 1. In the Control group, the root surface showed the directional change caused by root planing instrumentation, and the presence of smear layer, and no exposure of dentinal tubule was observed. Laser irradiated group showed surface changes with rough dentin surface of niche and depression and dentinal tubule exposure by the elimination of smear layer. 2. The micro-hardness of root surface in the laser irradiated group was higher than the control group. The higher energy output was applied, the higher micro-hardness on root surface was resulted. 3. The higher energy output was applied, the higher Ca/P ratio was observed. The higher Ca/P ratio in 60mJ group and 100mJ group was statistically significantly compared to the control group and the 30mJ group. These results suggest that Er:YAG laser irradiation on the periodontally diseased root surface could remove smear layer and increase the micro-hardness on root surface and Ca/P ratio which contribute to enhance the acid resistance of periodontally treated root surface.

• Applied Microscopy
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• v.30 no.2
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• pp.165-172
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• 2000

To investigate the defensive effect of green tea against the lead toxicity, Sprague-Dewley rats (150 gm) were divided into 5 groups; the control group, the group treated with lead for 4 weeks (Group A-1), the group treated with lead and green tea for 4 weeks (Group A-2), the group treated with lead for 8 weeks (Group B-1), and the group treated with lead and green tea for 8 weeks (Group B-2). The lead acetate (500 ppm) was injected two times for one week into the abdomen and green tea solution (3 g/100 ml distilled water) offered freely. In the liver cell, The cristae of mitochondria were enlarged, the rough endoplasmic reticulum (rER) extended and many lysosome observed on the Group A- 1. The cristae of mitochondria were enlarged and many lysosome observed, but nucleus was normal on the Croup A-2. All of observed parts on the Group B-1 deeply wounded by lead than the group A-1. In the Group B-2, the mitochondria and rER were increased in number than the Group B-1 and the nucleus was observed normally.

• Applied Microscopy
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• v.36 no.2
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• pp.57-72
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• 2006

A protective effect of activated charcoal against the acute lead poisoning of kidney was studied in mice. Mice approximately 30 gm in weight were grouped into the control, lead acetate-treated. and the activated charcoal-treated after lead acetate groups. Lead acetate (60mg/kg) and activated charcoal (40mg/kg) were delivered orally. Serum BUN and creatine were measured and ultrastructural alteration of renal tissues were examined by electron microscopy. Activated charcoal were decreased the increase of serum BUN and Creatinine level induced by lead. Lead acetate-treated renal tissues were characterized by the loss of microvilli in the renal tubule tells, irregular nucleus, enlarged and reduced number of mitochodria, enlarged rough endoplasmic reticulum, loss of ribosomes. Cells treated with activated charcoal were similar to those of the control group. In conclusion, activated charcoal may protect the lead-induced toxicity on kidney.

• Journal of Korean Society on Water Environment
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• v.29 no.4
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• pp.559-567
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• 2013

In recent years, NF (nanofiltration) membrane has been receiving great attention for hardness removal and has begun to replace traditional lime soda ash softening process, particularly in Florida, USA, mainly due to less sludge production and easy operation. This study aimed to provide detailed surface characteristics of various commercial NF membranes by performing sophisticated surface analysis, which would help more fundamentally understand the performance of NF membranes. More specifically, a total of 7 NF membranes from top NF/RO manufacturers in the world were examined for basic performance tests, surface analysis, and fouling potential assessment. The results demonstrated that NF membranes are classified into two groups in terms of surface zeta potential; they are highly negatively charged ones, and neutral and/or less negatively charged ones. Their hydrophobicities, measured by contact angle, varied from hydrophilic to slightly hydrophobic ones. The AFM measurements showed various surface roughness, ranging from 23 nm (smooth) to 162 nm (rough) of average peak height. Lab-scale fouling experiments were performed using feedwater obtained from conventional water treatment plants in the province of Korea, and their results attempted to correlate to surface characteristics of NF membranes. However, unlike typical RO membranes, no clear correlation was found in this study, indicating that fouling mechanisms of NF membrane may be different from those of typical RO membranes, and both cake deposition and pore blocking mechanisms should be considered simultaneously.