• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.4
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• pp.1301-1308
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• 1996

In order to save the energy and protect the environment, it were studied about ecomaterials with the developed countries as central figure. In the Metal Matrix Composites(MMCs), this trends appeared the development of the MMCs which had excellent mechanical properties in spite of the low volume fraction of reinforcement. Therefore, in this study, fatigue crack growth test, tensile and hardness test were conducted in order to investigate the mechanical and fatigue properties of 5 %, and 10 % $SiC_{p}$/Al composites. As the results, in the tensile and hardness test, tensile strength and hardness increased but fatigue crack growth rate decreased with $SiC_{p}$/Al volume fraction. And in the view of fatigue failured surface through the SEM, fatigue crack initiated around the SiC particle and in low $\Delta{K}$ regions, fatigue creck detoured the SiC particle but crack propagated through the SiC particle in the high $\DeltaK$ regions.

• Journal of Life Science
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• v.19 no.11
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• pp.1529-1537
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• 2009

To elucidate further the antitumor effects of a natural L-arginine analogue, L-canavanine, the mechanism underlying apoptogenic activity of L-canavanine and its modulation by protein tyrosine kinase $p56^{lck}$ was investigated in human Jurkat T cells. When the cells were treated with 1.25 to 2.5 mM L-canavanine for 36 h, several apoptotic events including mitochondrial membrane potential (${\Delta\Psi}m$) loss, activation of caspase-9, -3, -8, and -7, poly (ADP-ribose) polymerase (PARP) degradation, and DNA fragmentation were induced without alteration in the levels of Fas or FasL. These apoptotic changes were more significant in $p56^{lck}$-deficient Jurkat clone JCaM1.6 than in $p56^{lck}$-positive Jurkat clone E6.1. The L-canavanine-induced apoptosis observed in $p56^{lck}$-deficient JCaM1.6 cells was significantly reduced by introducing $p56^{lck}$ gene into JCaM1.6 cells by stable transfection. Treatment of JCaM1.6/lck cells with L-canavanine caused a transient 1.6-fold increase in the kinase activity of $p56^{lck}$. Both FADD-positive wild-type Jurkat T cell clone A3 and FADD-deficient Jurkat T cell clone I2.1 exhibited a similar susceptibility to the cytotoxicity of L-canavanine, excluding involvement of Fas/FasL system in triggering L-canavanine-induced apoptosis. The L-canavanine-induced apoptotic sub-$G_1$ peak and activation of caspase-3, -8, and -7 were abrogated by pan-caspase inhibitor (z-VAD-fmk), whereas L-canavanine-induced activation of caspase-9 was not affected. These results demonstrated that L-canavanine caused apoptosis of Jurkat T cells via the loss of ${\Delta\Psi}m$, and the activation of caspase-9, -3, -8, and -7, leading to PARP degradation, and that the $p56^{lck}$ kinase attenuated the ${\Delta\Psi}m$ loss and activation of caspases, and thus contributed as a negative regulator to L-canavanine-induced apoptosis.

• The Journal of Korean Academy of Prosthodontics
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• v.49 no.2
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• pp.161-167
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• 2011

Purpose: The purpose of this study was to evaluate the influence of porcelain re-firing on the formation of surface bubble and on the change in shade of metal-ceramic crown exposed to artificial saliva. Materials and methods: Thirty disk-shaped specimens were made in 10 mm diameter with 0.5 mm metal core thickness and 1 mm ceramic thickness. A spectroradiometer was used to determine the CIE Lab coordinates. The number and size of surface bubble were observed with a stereomicroscope. After the exposure to artificial saliva for 7 days, re-firing was performed at glazing temperature. After re-firing, the CIE Lab were calculated, and the number and size of surface bubble were observed again. The change in shade was expressed with ${\Delta}E$. Statistical analysis was done with paired t-test for the change in the number of surface bubble and student t-test for the change in the size of surface bubble (${\alpha$}=0.05). Results: Shade difference was calculated 2.14 ${\Delta}E$ units. The mean number of surface bubble was $1.33{\pm}1.49$ before re-firing, $3.27{\pm}2.90$ after re-firing. After re-firing, the number of surface bubble was significantly increased (P<.05). The mean size of surface bubble was $81.97{\pm}32.03\;{\mu}m$ before re-firing, $142.94{\pm}47.40\;{\mu}m$ after re-firing. After re-firing, the size of surface bubble was significantly increased (P<.05). Conclusion: Shade change after re-firing was perceptible (${\Delta}E$ < 2.0) and clinically acceptable (${\Delta}E$ < 3.7). The number and size of surface bubble was significantly increased after re-firing. Further investigation to decrease the surface bubble on the extra oral repair of metal-ceramic crown, will be needed in future study.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.580-586
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• 2010

The effects of persimmon, mulberry and bamboo leaves addition on the fermentative and sensory characteristics of kimchi were investigated. Total polyphenol content, DPPH radical scavenging activity and lactic acid bacteria growth inhibition of EtOH extract from persimmon leaves were significantly higher than those from mulberry and bamboo leaves. From the sensory evaluation of kimchi added with three chopped plant leaves, kimchi added with chopped persimmon leaves gave the highest point in color, flavor, texture and overall preference significantly (p<0.05). When the chopped persimmon leaves were added at a ratio of 0.3% based on cabbage weight, the changes of pH and total acidity (TA) during the storage for 14 days were significantly lowered, compared to general kimchi (p<0.05). Total polyphenol content and DPPH radical scavenging activity of kimchi supplemented with chopped persimmon leaves at 0.3% also significantly increased after storage for 14 days (p<0.05), and this kimchi provided higher total polyphenol content and DPPH radical scavenging activity than general kimchi. These results suggest that the addition of perisimmon leaves have significant influences on the fermentation and sensory characteristics of kimchi.

• The Korea Journal of Herbology
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• v.21 no.1
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• pp.51-56
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• 2006

Objectives : To clarify the effects of Actinidia polygama and CsA on OVA-induced asthma model, we examined the influence of Actinidia polygama fructus extract (APF) and CsA on the number of regulatory T cells, NKT cells and ${\gamma}{\delta}$ T cells in murine model of asthma. Methods : All mice were immunized on two different days (21 days and 7 days before inhalational exposure) by i.p. injections of OVA in PBS. Seven days after the second sensitization, mice were exposed to aerosolized ovalbumin for 30 min/day on 3 days/week for 12 weeks and APF (400, 40 mg/kg) were orally administered 3 times a week for 8 weeks. Results : The suppressive effects of APF on asthma model were demonstrated by the increase the number of regulatory T cells, ${\gamma}{\delta}$ T cells and by reducing the number of NK T cells. Conclusion : These results indicate that APF has a deep inhibitory effect on airway inflammation and hyperresponsiveness in murine model of asthma by increase the number of regulatory T cells, and ${\gamma}{\delta}$ T cells and by reducing the number of NK T cells.

• Science of Emotion and Sensibility
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• v.15 no.4
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• pp.453-468
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• 2012

This study investigated the effects of Lavandula angustifolia (L. angustifolia) aroma on the brain electrical activity evaluated by an electroencephalogram (EEG) in the male adults since many researches were performed with females and few with males. Sleep quality of 35 male adults were analyzed by Pittsburgh sleep quality index, and they were divided into two groups of good sleep quality and poor sleep quality. EEG electrodes were attached at the frontal (F3, F4), temporal (T3, T4), occipital (O1, O2), and parietal (P3, P4) regions according to the International 10-20 system. EEG was measured for 3 min per each period of before, during, and after L. angustifolia aromatherapy. Subjects with good sleep quality showed increases in the delta power at the parietal region of both cerebral hemispheres and in the theta power at the temporal region of right hemisphere (p<0.05), and a decrease in the alpha at the parietal region of both cerebral hemispheres (p<0.05). And subjects with poor sleep quality showed increases in the delta power at the frontal region of left cerebral hemisphere and in the theta power at the frontal region of both hemispheres (p<0.05). It is concluded that L. angustifolia aroma has effects on decreasing an awakening status related-brain wave and increasing the sleep status related-brain waves in the male adults with good sleep quality, and has also effects on increasing the sleep status related-brain waves in the male adults with poor sleep quality.

• Food Science of Animal Resources
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• v.32 no.6
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• pp.803-809
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• 2012

This study was carried out to evaluate the effects of whey ferment containing L. acidophilus KCCM 32820 and P. freudenreichii KCCM 31227 on the quality characteristics of white pan bread. Instrumental analysis such as alveograph, gelatinization temperature, texture analysis, retrogradation rate was determined. In an alveograph test, $P_{max}$ value in the treatment was higher than that in the control, but extensibility of dough in the control showed to be higher than in the treatment, so test dough showed more strength than the control. In terms of DSC analysis for gelatinization, temperature there were no significant differences of $T_p$ and ${\Delta}H$ between the control and the treatment. In hardness analysis by rheometer, dough containing whey ferment revealed lower values than the control. From the analysis of the organic acid contents, propionic acid was not detected in the control, however 1.13 mg/g of propionic acid was detected in the treatment. In the retrogradation analysis by DSC, the test delayed slightly compared to the control.

• Journal of the Korean Society of Groundwater Environment
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• v.6 no.4
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• pp.171-179
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• 1999

The $CO_2$-rich waters in the Chojeong area are characterized by low pH (5.0~5.8), high $CO_2$pressure (about 1 atm) and high amounts of total dissolved iou (up to 989 mg/L) and chemically belong to Ca-HC $O_3$type. The oxygen. deuterium and tritium isotope data indicate that the mixing process occurred between $CO_2$-rich water and surface water and/or shallow groundwaters and also suggest that the $CO_2$-rich water has been derived from meteoric waters. According to $\delta$$^{13}$ C values (-8.6~-5.3$\textperthousand$). the $CO_2$ in the water is attributed from deep seated $CO_2$gas. The high dissolved carbon (-14.4~-6.8$\textperthousand$. $\delta$$^{13}$ C) in groundwater of the granitic terrain might be affected by $CO_2$-rich water, whereas the dissolved carbon (-17.9~-15.2$\textperthousand$. $\delta$$^{13}$ C) in groundwater of the metamorphic terrain is likely controlled by soil $CO_2$ and from the reaction with calcite in phyllite. Sulfur isotope data (＋3.5~＋11.3$\textperthousand$,$\delta$$^{34}$ $S_{SO4}$) also support the mixing process between $CO_2$-rich water and shallow groundwater. Strontium isotopic ratio ($^{87}$ Sr/$^{86}$ Sr) indicates that the $CO_2$-rich water (0.7138~0.7156) is not related to vein calcite (0.7184) of Buak mine or calcite (0.7281~0.7346) in phyllite. By nitrogen isotope ($\delta$$^{15}$ $N_{NO3}$) the sources of nitrogen (up to 55.0 mg/L, N $O_3$) in the $CO_2$-rich water are identified as fertilizer and animal manure. It also indicates the possibility of denitrification during the circulation of nitrogen in the Chojeong area. The possible evolution model of the $CO_2$-rich water based on the hydrochemical and environmental isotopic data was proposed in this study. The $CO_2$-rich waters from the Chojeong area were primarily derived from the reaction with granite by supply of deep seated $CO_2$. and then the $CO_2$-rich water was mixed and diluted with the local groundwater.ter.

• Applied Biological Chemistry
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• v.36 no.3
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• pp.184-190
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• 1993

The effect of ${\delta}-aminolevulinic\;acid$ (ALA) biosynthetic precursors and related compounds on the ALA productivity from a strain of Rhodobacter sphaeroides has been examined in vivo and in vitro systems. The relative ratios of ALA productivities by $C_{4}$- pathway to that by $C_{5}$-pathway in vivo and in vitro systems were 0.78 and 1.37, respectively. Although the expression rates of $C_{4}-$ and $C_{5}-pathways$ in cell-free systems prepared after precursors supplemented cultivations were increased 1.35 and 1.52 folds, respectively, the rate increase of $C_{4}-pathway$ was accompanied by the rate decrease of the $C_{5}-pathways$, and vice versa, as that the rates of both $C_{4}-$ and $C_{5}-pathways$ were lowered to be 0.91, 0.83, respectively. The order of cellular uptake rates of ${\gamma}-glutamyl$ derivatives relative to that found with L-glutamic acid were shown to be D-glutamic acid, 0.55: D-glutamine, 0.5: L-glutamine, 0.4: ${\gamma}-L-glutamyl$ ethylester, 0.3: GSH and Glu-pNA, 0. L and D configurations of glutamine were indicated as better substrates in vivo for ALA yields than those of glutamic acid, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.32 no.2
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• pp.269-277
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• 2003

Effects of soy protein concentrate (SPC) containing isoflavone and casein diets on plasma phospholipid (PLs)-fatty acid patterns were investigated in 7-& 40- wk old female rats. Diets containing 16% SPC (soy/young:SY, soy/old: SO) and casein (casein/young : CY, casein/ old: CO) supplemented with 0.5% cholesterol were fed for 4 wks. Fatty acid compositions of plasma PLs were determined by TLC and GLC. Compared to the dietary protein effects, age effects on serum lipids were more profound. The levels of total cholesterol (Chol.), triglyceride, HDL-Chol., (LDL+VLDL)-Chol. and atherogenic index (AI) were higher in older groups (OC & OS) than younger groups (YC &. YS). Soy groups had higher Ell)L-Chol. level and lower (LDL+ VLDL)-Chol. and AI, compared with casein groups. The compositions of C22:0, Cl8:1 $\omega$9 and sum of MUFA in plasma PLs were significantly higher in casein group (CY & CO) than soy group (SY & SO), but those of sum of SFA were higher in soy group. The compositions of C22:0, Cl8:1 $\omega$9, C22:1, Cl8:3$\omega$3 and C22:4$\omega$6 were higher and those of C22:6$\omega$3, sum of $\omega$3, Cl8: 2$\omega$6 C20:4$\omega$6, sum of $\omega$6 and sum of PUFA were lower in plasma PLs of younger rats. The average P/S and $\omega$3/$\omega$6 ratio in older group was higher. The $\Delta$-7 desaturation index (16:0⇒16:1$\omega$7) and $\Delta$-9 desaturation index (18:0⇒18:1$\omega$9) were lower in soy group than casein group, while $\Delta$-6 and $\Delta$-5 desaturation index were not affected by dietary protein. The $\Delta$-4 desaturation index (22:4$\omega$6⇒22:5$\omega$6) were higher and elongation index (20:4$\omega$6⇒22:4$\omega$6) were lower in older group. The ratio of the products of $\omega$3 fatty acid series (Cl8:3) was significantly higher in older group, which indicated that age affected the plasma PUFA metabolism. On the other hand, older rats had higher serum cholesterol level compared with younger rats. Taken together, these changes in fatty acid composition might cause minimal changes in tile membrane fluidity induced by the increase serum cholesterol level.