• Journal of the Korean Crystal Growth and Crystal Technology
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• 제20권6호
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• pp.278-282
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• 2010

The doping effect of thulium on electrical properties and degradation behavior in barium titanate ceramics ($BaTiO_3$) was investigated in terms of generations of core-shell structure and micro-chemical changes through highly accelerated degradation test. The dielectric specimens of pellet type and multi-layered sheets were prepared by using $BaTiO_3$ with undoped and doped with 1 mol% $Tm_2O_3$. The $BaTiO_3$ ceramics doped with 1 mol% $Tm_2O_3$ had 40% higher dielectric constant (${\varepsilon}$ = 2700) than that of the undoped $BaTiO_3$ specimen at curie temperature and met X7R specification. According to the result of highly accelerated degradation test conducted at $150^{\circ}C$, 70 V, and 24 hr, the oxygen diffusion was declined in dielectrics doped with 1 mol% $Tm_2O_3$. The $Tm^{3+}$ ion substituted selectively Ba site and Ti site and contributed to the generation of the core-shell structure. Oxygen vacancies occurred by substitution for Ti site could reduce excess oxygen that reacted to the Ni electrode.

• The Korean Journal of Ceramics
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• 제3권1호
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• pp.43-46
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• 1997

Thulium (Tm) has been incorporated into $YAlO_3$ and $YTa_7O_{19}$ host materials to obtain blue phosphors. $Tm^{3+}$-doped $YAlO_3$ and $YTa_7O_{19}$ phosphors were prepared by the conventional solid state reaction method. According to the results of excitation and emission spectra measured at room temperature, the blue emission intensity of $Tm^{3+}$-doped $YTa_7O_{19}$, peaking at 455 nm was much higher than that of $Tm^{3+}-doped\; YAlO_34, peaking at 458 nm. The maximum of relative intensity of $Tm^{3+}-doped\; YAlO_3\; and\; YTa_7O_{19}$ was obtained at the doping concentration of 0.016 and 0.120 mol% $Tm^{3+}$, respectively. These emission spectra revealed the concentration quenching effect.

• BMB Reports
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• 제48권3호
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• pp.127-128
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• 2015

Tumor metastasis involves circulating and tumor-initiating capacities of metastatic cancer cells. Hepatic TM4SF5 promotes EMT for malignant growth and migration. Hepatocellular carcinoma (HCC) biomarkers remain unexplored for metastatic potential throughout metastasis. Here, novel TM4SF5/CD44 interaction-mediated self-renewal and circulating tumor cell (CTC) capacities were mechanistically explored. TM4SF5-dependent sphere growth was correlated with $CD133^+$, $CD24^-$, ALDH activity, and a physical association between CD44 and TM4SF5. The TM4SF5/CD44 interaction activated c-Src/STAT3/ Twist1/ B mi1 signaling for spheroid formation, while disturbing the interaction, expression, or activity of any component in this signaling pathway inhibited spheroid formation. In serial xenografts of less than 5,000 cells/injection, TM4SF5-positive tumors exhibited locally-increased CD44 expression, suggesting tumor cell differentiation. TM4SF5-positive cells were identified circulating in blood 4 to 6 weeks after orthotopic liver-injection. Anti-TM4SF reagents blocked their metastasis to distal intestinal organs. Altogether, our results provide evidence that TM4SF5 promotes self-renewal and CTC properties supported by $CD133^+/TM4SF5^+/CD44^+^{(TM4SF5-bound)}/ALDH^+/CD24^-$ markers during HCC metastasis.

• Journal of the korean academy of Pediatric Dentistry
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• 제43권1호
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• pp.44-50
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• 2016

The purpose of this study was to compare and evaluate the remineralization effect of three types of fluoride varnishes on demineralized enamel of primary teeth. 40 primary teeth were decalcified by soaking them in artificial acidic solution and stored at $37^{\circ}C$ for 7 days. Then 3 varnishes - Cavity shield$^{TM}$, V varnish$^{TM}$ and MI varnish$^{TM}$ were applied respectively one time a week, for 3 weeks on the demineralized enamel surface. For the first week, MI varnish$^{TM}$ showed the highest microhardness value, V varnish$^{TM}$ was in second position, and Cavity shield$^{TM}$ showed the lowest microhardness value. However, there was no significant difference among the three groups(p > 0.05). For the second week, V varnish$^{TM}$ showed the highest microhardness value, and MI varnish$^{TM}$ came next in second position noting no significant difference (p > 0.05). Cavity shield$^{TM}$ was significantly lower than the other groups (p < 0.05). For the third week, V varnish$^{TM}$ showed the highest microhardness value, noting a significant difference from the other groups (p < 0.05). MI varnish$^{TM}$ came next, while Cavity shield$^{TM}$ showed the lowest microhardness value. However, there was no significant difference between MI varnish$^{TM}$ and Cavity shield$^{TM}$ (p > 0.05). The increase in the microhardness of groups V varnish$^{TM}$ and MI varnish$^{TM}$ were higher than that of group Cavity shield$^{TM}$ (p < 0.05), while no significant difference was noted between groups V varnish$^{TM}$ and MI varnish$^{TM}$ (p > 0.05).

• Journal of the korean academy of Pediatric Dentistry
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• 제36권3호
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• pp.427-432
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• 2009

The aim of this study was to compare the shear-peel strength and the fracture site of 5 commercially available orthodontic band cements. One hundred molar bands were cemented to extracted human 3rd molars. The specimens were prepared in accordance with the manufacturer's instructions for each cement. After storage in a humidor at $37^{\circ}C$ for 24 hours, the shear debonding force was assessed for each specimen using an universal testing machine with crosshead speed of 2 mm/minute. Maximal failure stress was converted to mean shear-peel strength, MPa. The predominant site of band failure was recorded visually for all specimens as either at the band/cement or cement/enamel interface. Mean shear-peel strength of Ormco was the highest(2.44${\pm}$0.57), followed by Fuji $Ortho^{TM}$(2.24${\pm}$0.50), $Ketac-Cem^{TM}$(2.10${\pm}$0.57), 3M $Unitek^{TM}$(1.82${\pm}$0.43), $Band-Lok^{TM}$(1.73${\pm}$0.28). There were statistically significant differences between Ormco and $Band-Lok^{TM}$, Ormco and 3M $Unitek^{TM}$, and Fuji $Ortho^{TM}$ and $Band-Lok^{TM}$(p<0.05). The predominant site of bonding failure for bands cemented with the Ormco was at the band/cement interface, whereas bands cemented with Ultra $Band-Lok^{TM}$ failed predominantly at the enamel/cement interface. There was no significant difference among the other cements(Fuji $Ortho^{TM}$, 3M $Unitek^{TM}$, $Ketac-Cem^{TM}$).

• Korean Journal of Materials Research
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• 제28권6호
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• pp.355-360
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• 2018

$LuNbO_4:0.2Yb^{3+},xTm^{3+}$ powders were prepared using a solid-state reaction process. The effects of the amount of Tm on up-conversion(UC) and down-conversion(DC) luminescence properties are investigated. X-ray diffraction patterns confirm that $Yb^{3+}$ and $Tm^{3+}$ ions are successfully incorporated into Lu sites. Under 980 nm excitation, the UC spectra of the powders predominantly exhibit strong near-infrared emission bands that peak at 805 nm, whereas weak 480 nm emission bands are observed as well. The emission bands are assigned to the $^1G_4{\rightarrow}^3H_6$ (480 nm) and 3 $^3H_4{\rightarrow}^3H_6$ (805 nm) transitions of the $Tm^{3+}$ ions via an energy transfer from $Yb^{3+}$ to $Tm^{3+}$; two- and three-photon UC processes are responsible for the 805 and 480 nm emissions, respectively. The DC emission spectra exhibit blue emission ($^1D_2{\rightarrow}^3F_4$) of $Tm^{3+}$ at 458 nm. The amount of Tm affects the emission intensity with the strongest emissions at x = 0.007 and 0.02 for the UC and DC luminescence, respectively. The results demonstrate that $LuNbO_4:Yb^{3+},Tm^{3+}$ phosphors are suitable for bio-applications.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 한국환경생물학회 2001년도 학술대회
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• pp.128-128
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• 2001

• Journal of the Korean Association of Geographic Information Studies
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• 제4권1호
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• pp.18-26
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• 2001

Landsat TM band ratio algorithms were made by in-water optical measurement data of each sampling points for water quality monitoring of coastal area using Landsat TM satellite data. The algorithm was derived from in-water optical reflectance data which was measuring by the PRR(profiling reflectance radiometer). And, in-water optical reflectance data were applied to Landsat TM bands. Relationship between in-water optical reflectance and pigments proposed by the ratio of TM band 1 and band 2 showed to as follows; $Y=3.8352{\times}(R(band\;1)/R(band\;2))^{-2.1978}$ ($R^2$=0.7069) and, relationship of the ratio of TM band 1 and band 3 as follows; $Y=23.288{\times}(R(band\;1)/R(band\;3))^{-1.5243}$ ($R^2$=0.8062). Calculated the upwelling radiance of water surface and radiance of TM showed the ratio of atmospheric effect. In the coastal area Rayleigh and Mie scattering of atmosphere is to make over 80% of normalized radiance of Landsat TM. In order to apply in-water algorithm obtained by PRR, we had to calculate the atmospheric effects at sampling site. And, the quantitative analysis of in-water components using Landsat TM data need the calibration of in-water algorithm and effective method of atmospheric correction.

• Applied Chemistry for Engineering
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• 제8권4호
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• pp.637-639
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• 1997

Samples of $YTa_7O_{19}$ doped with $Tm^{3+}$ were prepared using the solid state reaction method to investigate their photoluminescence characteristics. The samples were identified by XRD and SEM, and the optical measurement was also carried out. Under 359 nm excitation, $YTa_7O_{19}$ doped with $Tm^{3+}$ exhibited a narrow-band blue emission, at about 455 nm. The maximum emission intensity was obtained at $YTa_7O_{19}$ doped with 0.12 mole $Tm^{3+}$. This revealed the concentration quenching of emission intensity.

• Korean Journal of Agricultural and Forest Meteorology
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• 제2권1호
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• pp.9-15
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• 2000

The objective of this study is to evaluate the use of RADARSAT and Landsat TM data for the monitoring of rice growth. The relationships between backscatter coefficients($\sigma$$^{0}$ ) of RADARSAT data and digital numbers (DN) of Landsat TM and rice growth parameters were investigated. Radar backscatter coefficients were calculated by calibration process and then compared with rice growth parameters; plant height, leaf area index (LAI), and fresh and dry biomass. When radar backscatter coefficient ($\sigma$$^{0}$ ) of rice was expressed as a function of time, it is shown that the increasing trend ranged from -22--20dB to -9--8dB as growth advances. The temporal variation of backscatter coefficient was significant to interpret rice growth. According to the relationship between leaf area index and backscatter coefficient, backscatter coefficient underestimated leaf area index at the beginning of life history and overestimated, at the reproductive stage. The same increasing trend between biomass and backscatter coefficient was shown. From these results, RADARSAT data appear positive to the monitoring of rice growth. Each band of time-series Landsat TM data had a significant trend as a rice crop grows during its life cycle. Spectral indices, NDVI[(TM4-TM3)/(TM4+TM3)] and RVI(TM4/TM2), derived from Landsat TM equivalent bands had the same trend as leaf area index.