• Journal of the Korean Chemical Society
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• v.54 no.3
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• pp.291-294
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• 2010

In this study, we demonstrated high-efficiency blue organic light-emitting diodes (OLEDs) employing BCzVBi as a blue fluorescent dye doped into blue host material, DPVBi with various concentration. The optimized blue OLED device having high-efficiency was constructed with structure of NPB (500 ${\AA}$) / DPVBi:BCzVBi-6% (150 ${\AA}$)/$Alq_3$(300 ${\AA}$) / Liq (20 ${\AA}$) / Al (1000 ${\AA}$). The maximum luminescence of blue OLED was 13200 cd/$m^2$ at 13.8 V and current density and maximum efficiency were 26.4 mA/$cm^2$ at 1000 cd/$m^2$ and 4.24 cd/A at 3.9 V, respectively. Luminous efficiency shows two times higher than comparing with non-doped BCzVBi blue OLED whereas $CIE_{x,y}$ coordinate was similar with bare DPVBi blue OLED such as (0.16, 0.19). Electroluminescence of BCzVBi-6% doped blue OLED has two major peaks at 445 nm and 470 nm whereas pure DPVBi's blue peak appears at 456 nm and it is happened through endothermic Forster energy transfer by molecule's vibration between LUMO of DPVBi as host material and LUMO of BCzVBi as dopant in device.

• Journal of Yeungnam Medical Science
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• v.10 no.2
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• pp.409-416
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• 1993

In the method for lithium (Li) analysis, flame emission photometry and atomic absorption spectrophotometry (AAS) have been used most frequently. In addition, lithium can be analyzed by ion-selective electrode (ISE) or fluorscence polarization immunoassay. We evaluated the comparison between AAS method based on the principle of absorption of light at 670.8 nm by Li and ISE method based on the principle of voltage difference generated by Li in contact with lithium ionophore. We compared with those obtained by AAS (AA/AE Spectrophotometer 551, Instrumentation Laboratory Co.) and ISE(CSYNCHRON EL-ISE, Beckman Co.) in the serum and urine of 6 patients and evaluated time-related changes of serum lithium concentration after dosing in both methods. The results are summarized as follows : 1. In within-run precision study for lithium concentration, coefficient variations (CVs, %) ranged from 1.34 to 2.17 for AAS and from 0.34 to 0.85 for ISE method. In between-run precision study for lithium concentration, CVs ranged from 1.23 to 1.72 for AAS and from 0.61 to 1.38 for ISE method. 2. The correlation study between AAS and ISE method resulted in Y=0.946X+0.137 (N=32, r=0.933, X=AAS, Y=ISE) for serum lithium and Y=1.092X+0.977 (N=28, r=0.943, X=AAS, Y=ISE) for urine lithium. 3. Time-related changes of serum lithium concentration in both AAS and ISE method resulted in peak serum levels about 2 hours after dosing and then rapidly decreased after the peak serum level and finally arrived at nearly initial levels about 9 hours after dosing. 4. The reference range of serum lithium was found as undetectable level for both AAS and ISE method and the reference range of urine lithium to the urine creatinine was 0-0.00014 mmol/mg(mean 0.00002 mmol/mg) for AAS method.

• Journal of Periodontal and Implant Science
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• v.36 no.4
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• pp.797-808
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• 2006

Objective : The purpose of this study was to evaluate the physicochemical properties and cytocompatibility of microporous, spherical biphasic calcium phosphate(BCP) ceramics with a 60/40 $hydroxyapatite/{\beta}$ -tricalcium phosphate weight ratio for application as a bone graft substitute. Materials and Methods : Microporous, spherical BCP granules(MGSB) were prepared and their basic characteristics were compared with commercially available BCP(MBCP; Biomatlante, France) and deproteinized bovine bone mineral(Bio-Oss; GBistlich-Pharma, Switzerland, BBP; Oscotec. Korea), Their physicochemical properties were evaluated by scanning electron microscopy, X-ray diffractometry, Fourier-transform infrared spectroscopy, inductively coupled plasma atomic emission spectrometer, and Brunauer-Emmett-Teller method. Cell viability and proliferation of MC3T3-El cells on different graft materials were evaluated. Results : MGSB granules showed a chemical composition and crystallinity similar with those in MBCP, they showed surface structure characteristic of three dimensionally, well-interconnected micropores. The results of MTT assay showed increases in cell viablity with increasing incubation times. At 4d of incubation, MGSB, MBCP and BBP showed similar values in optical density, but Bio-Oss exhibited significantly lower optical density compared to other bone substitutes(p <0,05). MGSB showed significantly greater cell number compared to other bone substitutes at 3, 5, and 7d of incubation(p <0,05), which were similar with those in polystyrene culture plates. Conclusion: These results indicated the suitable physicochemical properties of MGSB granules for application as an effective bone graft substitute. which provided compatible environment for osteoblast cell growth. However, further detailed studies are needed to confirm its biological effects on bone formation in vivo.