• Journal of Life Science
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• v.20 no.5
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• pp.745-749
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• 2010

This study was conducted to examine the effect of cytokinin ($N^6$-benzyladenine; BA) and/or an IAA on ethylene production of maize (Zea mays) primary roots. When the two hormones were applied exogenously, both hormones synergistically increased ethylene production, which was greater than the sum of the level of each hormone's effect. For example, the ethylene production was stimulated between about 87% and 170% of the control by $10^{-4}\;M$ BA with $10^{-4}\;M$ IAA for 8 hours respectively, whereas the ethylene production was increased by about 480% of the control when the two hormones were treated simultaneously. Such a synergistic effect was also found in changes in the activity and gene expression level of ACC synthase. However, in the case of ACC oxidase did not show any observable effects. Based on our results, it is possible to conclude that BA and IAA stimulated the ethylene production synergistically by affecting the ACC synthase in maize roots.

• Journal of the Korean Ceramic Society
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• v.51 no.6
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• pp.623-628
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• 2014

Orthorhombic $Ba(Ti_{0.94}Zr_{0.06})O_3$ single crystals are fabricated using the cost-effective solid-state single crystal growth (SSCG) method; their dielectric and piezoelectric properties are also characterized. Measurements show that (001) $Ba(Ti_{0.94}Zr_{0.06})O_3$ single crystals have an electromechanical coupling factor ($k_{33}$) higher than 0.83, piezoelectric charge constant ($d_{33}$) of about 400 [pC/N], and piezoelectric voltage constant ($g_{33}$) higher than 50 [${\times}10^{-3}Vm/N$]. The transition temperature ($T_{OT}$) of the (001) $Ba(Ti_{0.94}Zr_{0.06})O_3$ single crystals between orthorhombic and tetragonal phases is also observed to be about $61^{\circ}C$. Because their electromechanical coupling factor ($k_{33}$) and piezoelectric voltage constant ($g_{33}$) are higher than those of soft PZT ceramics, it is expected that (001) $Ba(Ti_{0.94}Zr_{0.06})O_3$ single crystals can be used as "lead-free" piezoelectric materials in many piezoelectric applications.

• Polymer(Korea)
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• v.31 no.2
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• pp.141-147
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• 2007

Dental properties of polymer composite loaded with hybrid filler of barium silicate (BaSi) and hydroxyapatite, which is a principal component of human bone material, were investigated. A visible light system was utilized to activate the acrylic resin matrix of the composite. Based on the experimental results, it was found that mechanical strength of the composite was consistently increased with an increase of BaSi content in the hybrid filler. And those value rose above the dental specification enough to apply for dental materials. However, abrasion resistance was slightly decreased with increasing BaSi content in the filler. Depth of cure value was 6 to 9 mm applicable for dental restoration irrelevant to hybrid filler composition. On the other hand, there was no strict trend between filler composition and polymerization shrinkage as well as degree of conversion.

• Journal of Preventive Medicine and Public Health
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• v.44 no.6
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• pp.260-266
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• 2011

Objectives: We evaluated the association between common carotid artery intima-media thickness (CCA-IMT), brachialankle pulse wave velocity (baPWV), carotid plaque, and peripheral arterial disease (PAD) as indicators of macroangiopathy and diabetic retinopathy as an indicator of microangiopathy in type 2 diabetic patients. Methods: We analyzed 605 type 2 diabetic patients registered at a public health center in Korea. Following overnight fasting, venous blood and urine samples were collected and analyzed. The CCA-IMT, levels of carotid plaque, baPWV, and ankle-brachial index (ABI) of the subjects were assessed. We used non-mydriatic fundus photography to diagnose diabetic retinopathy. Multiple logistic regression analyses were used to evaluate the association between macroangiopathy and diabetic retinopathy. CCA-IMT and baPWV were divided into tertiles: CCA-IMT, 0.39 to 0.65 mm, 0.66 to 0.78 mm, and 0.79 to 1.30 mm; baPWV, 9.9 to 15.8 m/s, 15.9 to 18.9 m/s, and 19.0 to 38.0 m/s. Results: The association between baPWV and diabetic retinopathy remained significant after adjustment, with an increasing odds ratio (OR) in the second tertile (OR, 2.41; 95% confidence interval [CI], 1.27 to 4.55) and the third tertile (OR, 4.63; 95% CI, 2.33 to 9.21). No significant differences were observed in carotid plaque, PAD, and each tertile of CCA-IMT. Conclusions: BaPWV was associated with diabetic retinopathy, while CCA-IMT, carotid plaque, and PAD were not. This study suggests that the association between macroangiopathy and microangiopathy may be attributable to functional processes rather than structural processes within the vascular system.

• Asian Journal of Turfgrass Science
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• v.9 no.3
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• pp.213-223
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• 1995

The study is aimed to understand effects of ethephon(lmg/1), ABA(0.lrng/l), BA(0.lmg/l). and NAA (0.lmg /1) soaking treatment on the seed germination of perennial ryegrass 'Dandy', creeping bentgrass 'Penlinks', tall fescue 'Arid' and kentucky bluegrass 'Nasaw'. These experiments are carried in vitro and their results are summarized as the followings ; In case of ethephon (lmg /1) soaking treatment of seed, the early germination of tall fescue 'Arid' and perennial ryegrass 'Dandy' was good without the soaking times. creeping bentgrass 'Penlinks' and kentucky bluegrass 'Nasaw' obtained the best results at 12 hr. soking treatment, and the longer the soaking time, the higher the germination percentage. The early germination percentage of tall fescue 'Arid' and perennial ryegrass 'Dandy' increased more highly at ABA(0. tmg /1) soaking treatment than at the control. The germination percent-age of creeping loentgrass 'Penlink' and kentucky bluegrass 'Nasaw' had respectively the best results at 6hr. and l2hr. soaking treatment. The early germination percentage of tall fescue 'Arid' and kentucky bluegrass 'Nasaw'increased more highly at BA (0.lmg /1) soaking treatment than at the control, and especially had the best results in 6hr. soaking treatment. perennial ryegrass 'Dandy' had the best results at l0min. soaking treatment, and the longer the soaking time, the lesser the germination percentage. The early germination of perennial ryegrass 'Dandy'. creeping bentgrass 'Penlinks' and tall fes- cue 'Arid' increased more highly at NAA (0.lmg /1) soaking treatment than at the control, and especially had the best results at l2hr. soaking treatment. However, the germination of Kentucky bluegrass 'Nasaw' seeds inhibited at NAA (0.lmg /1) soaking treatment. Key words: Ethephon, ABA, BA, NAA, Soaking treatment, Seed germination.

• Korean Journal of Materials Research
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• v.29 no.6
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• pp.356-362
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• 2019

$BaSiO_3:RE^{3+}$ (RE = Sm or Eu) phosphor powders with different concentrations of activator ions are synthesized using the solid-state reaction method. The effects of the concentration of activator ions on the structural, photoluminescent, and morphological properties of the barium silicate phosphors are investigated. X-ray diffraction data reveals that the crystal structure of all the phosphors, regardless of the type and the concentration of the activator ions, is an orthorhombic system with a main (111) diffraction peak. The grain particles agglomerate together to form larger clusters with increasing concentrations of activator ions. The emission spectra of the $Sm^{3+}$-doped $BaSiO_3$ phosphors under excitation at 406 nm consist of an intense orange band at 604 nm and three weak bands centered at 567, 651, and 711 nm, respectively. As the concentration of $Sm^{3+}$ increases from 1 to 5 mol%, the intensities of all the emission bands gradually increase, reach maxima at 5 mol% of $Sm^{3+}$ ions, and then decrease significantly with further increases in the $Sm^{3+}$ concentration due to the concentration quenching phenomenon. For the $Eu^{3+}$-doped $BaSiO_3$ phosphors, a strong red emission band at 621 nm and several weak bands are observed. The optimal orange and red light emissions of the $BaSiO_3$ phosphors are obtained when the concentrations of $Sm^{3+}$ and $Eu^{3+}$ ions are 5 mol% and 15 mol%, respectively.

• Microbiology and Biotechnology Letters
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• v.28 no.1
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• pp.8-13
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• 2000

A study was carried out to determine the probiotic effect of Lactobacillus reuteri BSA-131 by investigating the growth performance and fecal microbial population of piglets. Five dietary treatment groups, the basal diet (control, BD), basal diet with antibiotics(BA), basal diet with 2$\times$106/g of probiotics (BP6), 2$\times$108/g of probiotics (BP8) and basal diet with antibiotics and 2$\times$108/g probiot-ics(BAP8) were divised. Each dietary treatment group was consisted of 1 month of age piglets(male 13, female 12). Fecal micro-flora, body weights and feed consumption were measured at before, after and stop feeding of probiotics. The results showed that the CFU of fecal Enterobacteriaceae of piglets of the group BA, BP6, BP8 and BAP8, were reduced (P<0.05) compared to control BA. On the contrary, Lactobacillus counts were increased significan시 (P<0.001) in all groups fed probiotics dites, but not antibiotics. Body weight of probiotics treated piglets were improved 5% (p<0.001) in BP6 group than that of control group and antibiotic treated piglets BAP group was 27% (P<0.001) higher than BA group. The amount of feed consumption value of probiotics treated piglets showed 21-30% (P<0.001) lower intake than the control group, whereas antibiotic treated piglets BAP was 20% (P<0.001) higher than BA group. The results showed that body weights and feed to gain ratios were improves 19% when compared to control piglets for groups fed diets probiotic. It is very suggestive that productivity of probiotic piglets would be economical in pig farming.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.8
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• pp.680-684
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• 2007

In this study, we investigated the effects of structural and electrical properties of $(Ba_{0.6},\;Sr_{0.3},\;Ca_{0.1})TiO_3$ thick films with variation $Dy_2O_3$ contents. $(Ba_{0.6},\;Sr_{0.3},\;Ca_{0.1})TiO_3$ powders, prepared by the sol-gel method, were mixed organic vehicle. The BSCT thick films doped with 0.1, 0.3, 0.5, 0.7 mol% $Dy_2O_3$ were fabricated by the screen-printing techniques on the alumina substrates and the structural and dielectric properties were investigated with variation of $Dy_2O_3$ doping contents. All BSCT thick films were sintered at $1420^{\circ}C$, for 2hr. In the TG-DTA analysis, the formation of the polycrystalline perovskite phase was observed at around $670 ^{\circ}C$. In the XRD analysis, all BSCT thick films showed the cubic perovskite structure. The average thickness of BSCT thick films was approximately $65{\mu}m$. The Curie temperature decreased with increasing $Dy_2O_3$ amount. The relative dielectric constant and dielectric loss of BSCT thick films doped with $Dy_2O_3$ 0.1 mol% were 6267 and 2.6 %, respectively.

• Journal of the Korean Ceramic Society
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• v.36 no.6
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• pp.590-598
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• 1999

• Journal of the Korean Magnetics Society
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• v.6 no.2
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• pp.73-79
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• 1996

Y-type hexagonal ferrites$(Ba_{2}Me_{2}Fe_{12}O_{22}:Me=transition metal)$ have promising electromagnetic properties in GHz range. Co and Zn are good candidates for the transition metal. To understand their role on the properties, it is thus necessary to study the ion(s) distribution in that complex Y-type hexagonal ferrite structure. The authors report Mossbauer spectroscopic results from very reliable samples, which has been extensively characterized by chemical analysis, Rietveld analysis of X-ray diffraction patterns, and magnetic property measurements. Analyzing two samples, $Co_{2}Y$ and $Co_{1.6}Zn_{0.4}Y$, conclusions are made as follow: (1) Co ions prefer the tetrahedral interstitial sites in the S-block $(6c_{IV})$ and the octahedral sites $(18h_{VI})$ at the interface of S- and T-block. (2) Partial substitution of Co with Zn (within the experimental range) does not disturb the Fe distribution.