• The Korean Journal of Physiology
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• v.29 no.2
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• pp.301-307
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• 1995

To explore electrophysiological properties of the ${\delta}-Opioid$ receptors artificially expressed in the mammalian cell, effect of an opioid agonist DPDPE $(1\;{\mu}M)$ on the voltage-sensitive outward currents was examined in the HEK293 (human embryonic kidney) cells transfected with ${\delta}-Opioid$ receptor cDNA cloned from NG-108-15 $(neuroblastoma\;{\times}\;glioma\;hybrid)$ cDNA library. Also studied were effects of 8-bromo-cyclic AMP and naloxone on DPDPE-induced changes in the voltage sensitive outward current. The voltage sensitive outward currents were recorded using perforated patch technique at room temperature. In the non-transformed HEK293 cells, DPDPE did not alter voltage sensitive outward current, indicating that no native ${\delta}-Opioid$ receptor had been developed. However, $(1\;{\mu}M)$ DPDPE remarkably increased the voltage sensitive outward current in the transformed HEK293 cells. The increment in voltage sensitive outward current peaked in $7{\sim}10\;minutes$ after DPDPE application, and the maximum DPDPE-activated outward current $(313.1{\pm}12.3\;pA)$ was recorded when the membrane potential was depolarized to +70mv. Following pretreatment of the transformed HEK293 cells with 1 mM 8-bromo-cyclic AMP, DPDPE failed to increase the voltage sensitive outward currents. On the other hand, naloxone completely abolished DPDPE-activated voltage sensitive outward current in the transformed HEK293 cells. The results of present study suggest that in the transformed HEK293 cells an activation of the ${\delta}-Opioid$ receptors by an opioid agonist DPDPE increases the voltage-sensitive potassium current as a result of decrement in cyclic AMP level.

• Journal of Microbiology and Biotechnology
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• v.23 no.8
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• pp.1099-1106
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• 2013

Tuta absoluta (Povolny, 1994) is a devastating moth to the Solanaceae plants. It is a challenging pest to control, especially on tomatoes. In this work, we studied the entomopathogenic activity of the Cry-forming ${\delta}$-endotoxins produced by Bacillus thuringiensis strain KS and B. thuringiensis kurstaki reference strain HD1 against T. absoluta. These strains carried the cry2, cry1Ab, cry1Aa/cry1Ac, and cry1I genes, and KS also carried a cry1C gene. The ${\delta}$-endotoxins of KS were approximately twofold more toxic against the third instar larvae than those of HD1, as they showed lower 50% and 90% lethal concentrations (0.80 and 2.70 ${\mu}g/cm^2$ (${\delta}$-endotoxins/tomato leaf)) compared with those of HD1 (1.70 and 4.50 ${\mu}g/cm^2$) (p < 0.05). Additionally, the larvae protease extract showed at least six caseinolytic activities, which activated the KS and HD1 ${\delta}$-endotoxins, yielding the active toxins of about 65 kDa and the protease-resistant core of about 58 kDa. Moreover, the histopathological effects of KS and HD1 ${\delta}$-endotoxins on the larvae midgut consisted of an apical columnar cell vacuolization, microvillus damage, and epithelial cell disruption. These results showed that the KS strain could be a candidate for T. absoluta control.

• Progress in Medical Physics
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• v.8 no.1
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• pp.3-15
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• 1997

Adrenal chromaffin cells secrete catecholamine in response to acetylcholine. The secretory response has absolute requirement for extracellular calcium, indication that $Ca^{2+}$ influx through voltage dependent $Ca^{2+}$ channel (VDCC) is the primary trigger of the secretion cascade. Although the existence of various types of $Ca^{2+}$ channels has been explored using patch clamp technique in adrenal chromaffin cells, the contribution of different types of $Ca^{2+}$ channels to catecholamine secretion remains to be established. To investigate the quantative contribution of different types of $Ca^{2+}$ channels to cate-cholamine secretion, $Ca^{2+}$ current($I_{Ca}$) and the resultant membrane capacitance increment($\Delta{C}_{m}$) were simultaneoulsy measured. Software based phasor detector technique was used to monitor $\Delta{C}_{m}$. After blockade of L type VDCC with nicardipine (1$\mu$M), $I_{ca}$ was blocked to 43.85$\pm$6.72%(mean$\pm$SEM) of control and the resultant ㅿC$_{m}$ was reduced ot 30.10$\pm$16.44% of control. In the presence of nicardipine and $\omega$-conotoxin in GVIA(l$\mu$M), an N type VDCC antagonist, $I_{ca}$ was blocked to 11.62$\pm$2.96% of control and the resultant $\Delta{C}_{m}$ was reduced to 26.13$\pm$8.25% of control. Finally, in the presence of L, N, and P type $Ca^{2\pm}$ channel antagonists(nicardipine, $\omega$-Conotoxin GVIA, and $\omega$-agatoxin IVA, respectively), $I_{ca}$ and resultant $\Delta{C}_{m}$ were almost completely blocked. From the observation of parallel effects of $Ca^{2+}$ channel antagonists on $I_{ca}$ and $\Delta{C}_{m}$, it was concluded that L, N, and also P type $Ca^{2+}$ channels served and $Ca^{2+}$ source for exocytosis and no difference was observed in their efficiency to evoke exocytosis amost L, N, and P type $Ca^{2+}$ channels.

• Journal of Environmental Science International
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• v.26 no.3
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• pp.363-371
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• 2017

This study evaluates the adsorption properties of Sr ions in an aqueous solution of the synthetic zeolite (Z-Y1) prepared using coal fly ash generated from a thermal power plant. In order to investigate the adsorption characteristics, the effects of various parameters such as the initial concentrations of Sr ion, contact time, and solution pH were investigated in a batch mode. The Langmuir and Redlich-Peterson model fitted the adsorption isotherm data better than the Freundlich model. The maximum adsorption capacity of Sr ions, as determined the Langmuir model, was 181.68 mg/g. It was found that by varying the Sr ion concentration, pH, and temperature, the pseudo-second-order kinetic model describes the adsorption kinetics of the Sr ion better than the pseudo-first-order kinetic model. The calculated thermodynamic parameters of ${\Delta}H^0$ and ${\Delta}G^0$ showed that the adsorption of Sr ions on Z-Y1 was occurred through a spontaneous and an endothermic reaction. We found that the adsorption of Sr ions by Z-Y1 was more affected by pH than by temperature and Sr ion concentration.

• Transactions of the Korean Society of Mechanical Engineers
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• v.16 no.8
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• pp.1493-1502
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• 1992

The purpose of this study is to identify the effects of loading variables on fatigue crack opening behavior, using structural steel SS41. To use various stress ratios, three kinds of the methods varying stress ratio were used; .DELTA.P const., P$_{max}$ const., and P$_{min}$ const.. To measure the opening load, the direct measuring method which measures the distance between two micro indentations 20 .mu.m behind crack tip and the elastic compliance method were used. As the results of present study, the following conclusions are obtained. First, using the direct measuring method, it was possible to measure the COD at any location behind crack tip. Second, as measuring point becomes farther from crack tip, opening load becomes smaller. Third, the acceleration of da/dN near notch is due to crack opening behavior. Finally, opening ratio is a function of not only R, but .DELTA.K.K.K.

• Korean Journal of Acupuncture
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• v.20 no.3
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• pp.9-27
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• 2003

Objectives : The aim of this study was to examine the effects of electro-acupuncture(EA) at the SP6(Sameumgyo)-GB39(Hyeonjong) on normal human EEG using power spectral analysis. Methods : EEG power spectrum exhibit site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity(LAXTHA Co., KOREA). 30 channel EEG study was carried out in 20 subjects $(20\;males;\;age=21.4{\pm}0.5\;years)$. Results : In $\alpha$(alpha) band, the power values at F4 channels(p<0.05) during the SP6-GB39 acupoints treatment was significantly increased. But, the power values at Fz channel during the non-acupoint treatment was significantly decreased . In $\beta$(beta) band, the power values at Fz, FTC1, T3 channels(p<0.05) was significantly increased during the SP6-GB39 acupoints treatment. In $\delta$(delta) band, the power values at F4, C3, Cz, CP1, Pz channels(p<0.05) during SP6-GB39 acupoints treatment were significantly decreased.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.4
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• pp.174-181
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• 2005

In order to investigate the behavior of fatigue crack growth of SiC-particulate- reinforced Al-Si alloy composites, fatigue tests using single edge notched tension(SENT) specimens were performed. Composite materials were manufactured by using both permanent die casting and extrusion processes with different volume fractions of $10\%\;and\;20\%$. $SiC_p-reinfurced$ Al-Si composites showed the increased levels of threshold stress intensity factor range, ${\Delta}K_{th}$, for the increased volume fractions of SiC particles, which implies the increased fatigue crack growth resistance at the threshold or low ${\Delta}K$ levels, compared to the unreinforced Al-Si alloy. In the Paris region, however, the composites showed the increased rate of crack growth resulting in the unfavorable effects on the fatigue crack growth resistance. Critical stress intensity factor range at unstable crack growth leading to final fracture decreased as the volume fraction of SiC particle increased, because of the reduced fracture toughness of the composites. Extruded materials showed higher threshold and critical values than the cast materials.

• The Journal of the Korea Contents Association
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• v.12 no.12
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• pp.616-626
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• 2012

Despite growing importance of emotional laborer management in broadcast artist, there are very few empirical studies on the effects thereof. The purpose of this study is to identify effects of emotional labor and job stress of broadcast artist on job satisfaction and their relations. Of the 200 distributed questionnaires 120 copies were used in the analysis. The results of the study were as follows. The results of the study showed that there exist strong relationship between emotional labor($r=-.226^*$) & job stress($r=-.505^{**}$) and job satisfaction. Emotional labor and job stress show significant effects on job satisfaction negatively(${\Delta}R2=.292$, F=5.557, p<.01). The implications of the results and research topics to be studied were discussed.

• Asian-Australasian Journal of Animal Sciences
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• v.21 no.9
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• pp.1355-1360
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• 2008

Effects of dietary ${\delta}$-aminolevulinic acid (ALA) supplementation on serum iron status, blood characteristics, egg production and quality were examined in laying hens in an 8-week feeding trail. Two hundred and forty (Hy-line brown, 40-week-old) layers were randomly assigned to four dietary treatments with ten replications (six layers in adjacent three cages). Dietary treatments included: 1) CON (basal diet), 2) ALA1 (CON+ALA 5 ppm), 3) ALA2 (CON+ALA 10 ppm) and 4) ALA3 (CON+ALA 15 ppm). All nutrient levels of diets were formulated to meet or exceed NRC (1994) recommendations for laying hens. During the entire experimental period, differences of serum iron concentration and total iron binding capacity (TIBC) were significantly increased in ALA1 supplemented treatment (quadratic effect, p<0.05). The difference of total protein between 8 and 0 weeks was significantly higher in ALA2 treatment than CON treatment (quadratic effect, p<0.05). No significant effects were observed on hemoglobin, WBC, RBC, lymphocyte and albumin concentrations. Egg production and egg weight were not influenced by the ALA supplementation. Egg yolk index was also significantly higher in ALA3 treatment than CON treatment at the end of 4 and 8 weeks (linear effect, p<0.05). Haugh unit was increased in ALA3 treatment compared to CON and ALA1 treatments at the end of 8 weeks (linear effect, p<0.05). However, egg shell thickness, breaking strength and yolk color unit were not affected by the ALA supplementation. In conclusion, dietary ALA supplementation at a level of 5 ppm can affect iron concentration in serum while higher levels (10 or 15 ppm) have some beneficial influences on blood profiles and egg quality.

• Journal of Pharmacopuncture
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• v.6 no.3
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• pp.91-106
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• 2003

Objectives : The aim of this study was to examine the effects of electroacupuncture(EA) at the PC6(Naegwan) and the TE5 (Oegwan) on nounal humans using power spectral analysis. Methods : EEG power spectrum exhibit site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 30 channel EEG study was carried out in 30 subjects(30 males ; age=23.7 years). Results : In ${\alpha}$(alpha) band, the power values at F7 channels(p<0.05) during the PC6-acupoint treatment were significantly were decreased. In ${\beta}$(beta) band, the power values at Fp1, Fz, TT1, T5, P3, P4, Po1, P02, O1, Oz, O2 channels(p<0.05) during the non-acupoint treatment and at Fp1, F4, F8 channels(p<0.05) during the TE5-acupoint treatment significantly were increased. In ${\theta}$(theta) band, the power values at Fp1 channels(p<0.05) during the non-acupoint treatment and at Oz channels(p<0.05) the TE5-acupoint treatment significantly were increased. but, the power values at F7 channels(p<0.05) during the non-acupoint treatment were significantly were decreased. In ${\delta}$(delta) band, the power values at TCP1, TCP2, CP1, T5 channels(p<0.05) during PC6-acupoint treatment were increased and the power values at F7, TT2 channels(p<0.05) during non-acupoint treatment were increased. but, the power values at the TE5-acupoint treatment significantly was decreased than the before-acupuncture treatment.