• Restorative Dentistry and Endodontics
• /
• v.26 no.2
• /
• pp.153-161
• /
• 2001

The purpose of this study was to evaluate microleakage of six current dentin bonding systems. In this in vitro study, class V cavities were prepared on buccal and lingual surfaces of thirty extracted human molars. Each margin was on enamel and dentin/cementum. Experimental teeth were randomly divided into six groups of 5 each. Group 1 : Scotchbond Multi-Purpose; Group 2 : Single Bond; Group 3 : Prime&Bond NT ; Group 4 : Clearfil Liner Bond 2 ; Group 5 : MAC Bond II ; Group 6 : One-up Bond F. The bonding agent and composite resin were applied to class V cavities according to manufacturer's directions. After thermocycling, the specimens were immersed in 0.5% basic fuchsin dye solution for 6 hours and sectioned longitudinally through the center of the restoration with a low speed diamond saw. The degree of microleakage was measured as the extent of dye penetration under the stereomicroscope at $\times$20. The data were analyzed using one way ANOVA. When significant differences found. multiple comparisons were made using Duncan's Multiple Range Test. The results of this study were as follows: 1. In all groups, leakage value seen at the enamel margin was significantly lower than that seen at the dentin margin(P<0.001). 2. At the enamel margin, none of the dentin bonding systems used in this study showed statistically significant difference in leakage values(P<0.05). 3. At the cementum margin, group 3 showed the highest leakage value, and others were decreased as group 5, 6, 4 in that order, and group 1, 2 showed the lowest leakage value. There was statistically significant difference between group 3 and the other groups except for group 5(P<0.05).

• Journal of Microbiology
• /
• v.35 no.2
• /
• pp.97-102
• /
• 1997

Cysteine desulfhydrase (EC 4.4.1.1.) was purified from the culture supernatant of Streptomyces albidoflavus SMF301 by hydroxyapatite, gel filtration and Resource Q ion-exchange chromatography with a purification fold of six identical subunits. The enzyme was stabilized by dithiothreitol and pyridoxal 5'-phosphate during the purification procedures. The optimum pH and temperature were pH 8.6 and 35$^{\circ}C$, respectively. The N-terminal amino acid sequence was identified as A-P-L-P-T-A-D-V-R-S-D-P-G-Y-R-E-W-L-G-E-A-V. The purified cystein desulfhydrase had a high substrate specificity toward cysteine, and exhibited no cystahionine $\gamma$-lyase activity. The $K_m$ value for cysteine was determined to be 0.37 mM.

• Journal of The Korean Astronomical Society
• /
• v.11 no.1
• /
• pp.31-36
• /
• 1978

Although Serkowski used a single value K=1.15 in representing all the observed interstellar linear polarization curves by his empirical relation $p({\lambda})/P_{max}$=exp (-K $1n^2({\lambda}_{max}/{\lambda})$), where $p_{max}$ is the maximum polarization at wavelength ${\lambda}_{max}$, we have noticed a meaningful variation in K from observations of 72 stars. By comparing K's with $P_{max}/E_{B-V}\;and\;with\;{\lambda}_{max}$, we have examined how the shape of the polarization curve is related with the degree of grain alignment on one hand, and with grain sizes on the other. We have shown that correlations between K, $P_{max}/E_{B-V}\;and\;with\;{\lambda}_{max}$, are consistent with the idea of Davis-Greenstein mechanism for grain alignment.

• Nonlinear Functional Analysis and Applications
• /
• v.27 no.2
• /
• pp.349-361
• /
• 2022

In this paper, we study the following nonlinear problem: $$\{-\Delta_{p}^{3}(x)u\;=\;{\lambda}V_{1}(x){\mid}u{\mid}^{q(x)-2}u\;in\;{\Omega},\\u\;=\;{\Delta}u\;{\Delta}^{2}u\;=\;0\;on\;{\partial}\Omega, $$ under adequate conditions on the exponent functions p, q and the weight function V₁. We prove the existence and nonexistence of eigenvalues for p(x)-triharmonic problem with Navier boundary value conditions on a bounded domain in ℝ^N. Our technique is based on variational approaches and the theory of variable exponent Lebesgue spaces.

• Journal of the Korean GEO-environmental Society
• /
• v.7 no.1
• /
• pp.55-66
• /
• 2006

Laboratory tests have revealed that the liquefaction resistance of sands depends strongly upon the degree of saturation, which is expressed in terms of the pore pressure coefficient, B. The velocity of compression waves(i.e. P-waves), which have been known to be influenced largely by the degree of saturation and can be measured conveniently in the field, appears as an indicator of saturation. In this paper, the Stokoe type torsional shear(TS) testing equipment is modified to saturate the specimen and measure the velocities of P-wave and S-wave and pore pressure buildup. The velocities of P-wave and S-wave for Toyoura sand from Japan is measured and compared at the various B-value (degree of saturation) which are partially saturated to fully saturated conditions. Additionally, the variation of the pore water pressure induced during undrained TS tests at the various B-value is measured and analyzed.

• Journal of Korean Ophthalmic Optics Society
• /
• v.10 no.1
• /
• pp.53-61
• /
• 2005

In this study, we measured Near Point of Convergence(N.P.C) tests, Phoria tests using Von Grafe method and relative convergence tests on 138 men and 162 women, so a total of 300 subjects aged between 8~45 to examine the improvement of the fusion vergence through visual training and obtained as follows. 1. According to the results, the near point of convergence of 57 (19%) subjects were shorter than 7cm, and 243 (81%) were 7cm or longer, having a problem in convergence. After visual training, the number of subjects have the value shorter than 7 cm increased from 57 to 111 (37%), and the number of those have the value 7cm or longer decreased significantly form 243 to 189 (63%). 2. The results of the measure of lateral Phoria at far distance by Von Grafe method showed orthophoria 18 (6%), exophoria 198 (66%), esophoria 84 (28%). After phoria test, we examined the N.R.C and P.R.C test. The results showed that the hope finger was improved after V.T using B.l, B.O card. 3. The results of the measure of lateral Phoria at near distance by Von Grafe method showed orthophoria 6 (2%), exophoria 222 (74%), esophoria 72 (24%). After phoria test, we examine the N.R.C and P.R.C test. The results showed that the hope finger was improved after V.T using B.I, B.O card.

• Journal of Nutrition and Health
• /
• v.35 no.1
• /
• pp.5-14
• /
• 2002

Alteration in the syntesis or enhanced inactivation of nitric oxide(NO) can induce impairment of endothelial cell function. Insulin dependent diabetes mellitus(IDDM) is characterized by impaired endothelial function and vascular disease. NO is produced through L-arginine pathway To elucidate the hypothesis that the decreased production on NO in IDDM reflects vascular damage and the NO production can be manipulated by either dietary fat(7% of kg diet) or the oral supplementation with L-arginine(2g/kg bw), plasma markers for vascular endothelial damage and plasma lipid profiles were measured in streptozotocin(STZ)-induced diabetic rats. Diabetic or normal Sprague-Dawley rats were fed 6 different experimental diets for 4 weeks(SO : soybean oil, SOA: soybean oil + L-arginine supplementation, BT : beef tallow, BTA_ beef tallow + L-arginine supplementation, OV olive oil, OVA : olive oil + L-arginine supplementation). Plasma glucose, total cholesterel, HDL-cholesterol, LDL-cholesterol and triglyceride were measured. Endothelial markers, plasma von Willebrand factor(vWf), thromboxane B$_2$, and 6-keto PGF1$\alpha$ of aorta were measured by ELISA. Plasma NO production was evaluated through the measurement of nitrite by EIA. Feeding saturated fatty acid(SFA, BT) increased relative liver size(RLS) in diabetic rats compared to either polyunsatunted fatty acid(PUFA, SO) or monounsaturated fatty acid(MUFA, OV) The supplementation of L-arginine inhibited the liver and kidney enlargement in olive oil find diabetic rats. Plasma glucose was lower in diabetic animal find the olive oil compared to fed beef tallow and the supplementation L-arginine decreased it in diabetic rats find beef tallow significantly(p < 0.05). Plasma TXB$_2$ levels were increased due to diabetes and the value of beef tallow group showed highest value. Plasma vWf concentration of beef tallow group was higher value in normal rats and was elevated more in diabetes. In diabetic groups, the vWf concentration of olive oil group was lower than beef tallow or soybean oil group. The supplementation of L-arginine in diabetic rats decreased plasma TXB$_2$ and vWf levels significantly(p < 0.05). NO production was higher in normal olive oil fed rats and was tend to be decreased in diabetic rats and the supplementation of L-arginine recovered to normal value(p < 0.05), Olive oil supplemented with L-arginine tended to lower plasma total cholesterol and LDL-cholesterol after 4 week treatment. These results suggest that generalized vascular endothelial changes based on plasma TXB$_2$and vWf occurs in diabetic rats. and olive oil with L-arginine supplementation contributes to a better control of the hyperglycemia, endothelial changes and hypercholesterolemia accompanying diabetes as compared with beef tallow or soy bean oil in this rat model.

• Journal of Applied Biological Chemistry
• /
• v.55 no.3
• /
• pp.163-167
• /
• 2012

The objective of this study was to determine the effects of Schisandra chinensis on the alcohol fermentation of Korean traditional rice wine 'Yakju', using various methods including alcohol contents, Hunter's color value, organic acid contents, pH value, and sugar contents. The observed results differed according to dosage and fermentation. The S. chinensis Yakju contained various organic acids such as citric, formic, lactic, malic, oxalic acid, shikimic, and succinic acids. In particular, the citric acid contents of S. chinensis Yakju were 9.22, 161.38, 339.28, 458.97, and 634.96 mg/100 mL at doses of 0, 5, 10, 15, and 20% (v/v) of S. chinensis, respectively. The pH of S. chinensis Yakju ranges from 4.11 to 3.57 according to the ratio of S. chinensis. As a result, the citric acid content and pH of S. chinensis Yakju were dependent on the concentration of S. chinensis. On the basis of the Redness value, the S. chinensis Yakju after fermentation (5.16) was approximately 1.8 times more effective than that before fermentation (2.86) at the concentration of 20% (v/v) of S. chinensis. However, S. chinensis has little or no influence on the sugar and alcohol contents of Yakju. These results indicated that S. chinensis was more efficient for improvement of quality characteristics of Yakju.

• Korean Journal of Food Science and Technology
• /
• v.27 no.4
• /
• pp.439-444
• /
• 1995

Preparative conditions and characteristics of six-vegetable and fruit juice were studied for the effects of mixing ratio, heat treatment and addition of sugar, salt and organic acid. The vegetables and fruit used were carrot(Ct), cabbage(Cg), pear(Pr), cucumber(Cr), celery(Cy) and dongchimi(Di). From the sensory results of mixing ratio of three of binary mixtures of Cg-Pr(1:3):Ct-Di(1:4):Cr-Cy(3:1), two ratios of 5.0:2.5:2.5(V-6A) and 6.0:2.0:2.0(V-6B) were suggested optimal for six-vegetable and fruit juice. Addition of 2% sucrose and 0.3% NaCl improved the preference significantly. The pH 4.0 for V-6A and pH 3.5 for V-6B were more prefered when pH was adjusted by citric acid. Heating the juice at $100^{\circ}C$ for 100 minutes slightly decreased pH and increased the acidity. Total solids and viscosity were also decreased by heating. All of those changes were more significant in V-6B than V-6A, probably due to lower pH. Heating the juice resulted in a slight decrease in L value and an increase in a and b values. Heating at $100^{\circ}C$ caused an increase in moldy flavor and a decrease in fresh vegetable flavor while heating at $80^{\circ}C$ for 20 minutes changed them little.

• Food Science and Preservation
• /
• v.15 no.5
• /
• pp.622-629
• /
• 2008

This study investigated changes in quality characteristics of wrap- and vacuum-packaged peeled lotus roots treated with strong acidic electrolyzed acid water (SAEW pH 2.58, ORP 1,128 mV, HClO 105.0 ppm) or low alkaline electrolyzed water (LAEW pH 8.56, ORP 660 mV, HClO 73.8 ppm) as immersion liquids prior to packaging and storage at 5C. Immersion of peeled lotus roots in SAEW and LAEW reduced initial microbial load by about 1 log compared to treatment with tap water (TW). Hardness differences on storage were observed. However, reduction in PPO activity by electrolyzed water was not reproducible. Changes in Hunter's color value and the color difference value ($\Delta$) of peeled lotus roots immersed in 0.5% (w/v) sodium metabisulfite (SMS) and electrolyzed water were smaller than those of roots treated with TW prior to storage. Sensory characteristics measured during storage were best-preserved in lotus roots previously immersed in 0.5% (w/v) SMS or electrolyzed water, compared to TW. Immersionin electrolyzed water and vacuum packaging preserves the quality of peeled lotus roots in terms of microbial, visual, and sensory aspects, at levels comparable to those offered by storage after treatment with 0.5% (w/v) SMS.