• Advances in nano research
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• v.3 no.2
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• pp.55-66
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• 2015

Crystalline $Ce^{3+}$ co-doped $LaPO_4$:RE ($RE=Dy^{3+}$, $Tb^{3+}$, $Eu^{3+}$, $Sm^{3+}$) and mix doped rare earth ions of $Dy^{3+}$, $Tb^{3+}$ and $Eu^{3+}$ were prepared by the polyol method at $150^{\circ}C$. Strongly enhance luminescence intensity is obtained with the co-doping of $Ce^{3+}$ with $LaPO_4$:$Dy^{3+}$ and $LaPO_4$:$Tb^{3+}$ due to charge transfer (CT) occurring from $Ce^{3+}$ to $Dy^{3+}$ and $Ce^{3+}$ to $Tb^{3+}$, where as there is no significant changes in luminescence intensity of $Ce^{3+}$ co-doped $Eu^{3+}$ and $Sm^{3+}$ doped $LaPO_4$ samples. The luminescence color can be tuned from green to white by varying the excitation wavelength for the mix ions $Ce^{3+}$, $Dy^{3+}$, $Tb^{3+}$ and $Eu^{3+}$ doped with $LaPO_4$.

• Biomedical Science Letters
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• v.20 no.3
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• pp.162-167
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• 2014

Tuberculosis (TB) is one of the major global health problems and it has been estimated that in 5~10% of Mycobacterium tuberculosis (MTB)-infected individuals, the infection progresses to an active disease. Numerous cytokines and chemokines regulate immunological responses at cellular level including stimulation and recruitment of wide range of cells in immunity and inflammation. In the present study, the mRNA expression levels of eight host immune markers containing of IFN-${\gamma}$, TNF-${\alpha}$, IL-2R, IL-4, IL-10, CXCL9, CXCL10, and CXCL11 in whole blood cells from active pulmonary TB patients were measured after T-cell mitogen (PHA) and MTB specific antigens (ESAT-6, CFP-10, and TB7.7). Among the TH1-type factors, IFN-${\gamma}$ mRNA expression was peaked at 4 h, TNF-${\alpha}$ and IL-2R mRNA expression was significantly high at the late time points (24 h) in active TB patients, TH2-type cytokine (IL4 and IL10) mRNA expression levels in both active TB and healthy controls samples did not changed significantly, and the mRNA expression of the three IFN-${\gamma}$-induced chemokines (CXCL9, CXCL10, and CXCL11) were peaked at the late time points (24 h) in active TB patients after MTB specific antigen stimulation. In conclusion, the mRNA expression patterns of the TB-related immune markers in response to the T-cell mitogen (PHA) differed from those in response to MTB specific antigens and these findings may helpful for understanding the relationship between MTB infection and host immune markers in a transcripts level.

• Korean Journal of Materials Research
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• v.26 no.3
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• pp.143-148
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• 2016

$CaAl_2O_4:RE^{3+}$(RE = Tb or Dy) phosphor powders were synthesized with different contents of activator ions $Tb^{3+}$ and $Dy^{3+}$ by using the solid-state reaction method. The effects of the content of activator ions on the crystal structure, morphology, and emission and excitation properties of the resulting phosphor particles were investigated. XRD patterns showed that all the synthesized phosphors had a monoclinic system with a main (220) diffraction peak, irrespective of the content and type of $Tb^{3+}$ and $Dy^{3+}$ ions. For the $Tb^{3+}$-doped $CaAl_2O_4$ phosphor powders, the excitation spectra consisted of one broad band centered at 271 nm in the range of 220-320 nm and several weak peaks; the main emission band showed a strong green band at 552 nm that originated from the $^5D_4{\rightarrow}^7F_5$ transition of $Tb^{3+}$ ions. For the $Dy^{3+}$-doped $CaAl_2O_4$ phosphor, the emission spectra under ultraviolet excitation at 298 nm exhibited one strong yellow band centered at 581 nm and two weak bands at 488 and 672 nm. Concentration-dependent quenching was observed at 0.05 mol of $Tb^{3+}$ and $Dy^{3+}$ contents in the $CaAl_2O_4$ host lattice.

• Journal of the Korean Chemical Society
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• v.46 no.4
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• pp.336-345
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• 2002

In this study, we have screened $Eu^{3+}$- and $Tb^{3+}$-activated candidate phosphors for PDP in the sys-tems of CaO-Gd$_2$O$_3$-Al$_2$O$_3$ by combinatorial chemistry and investigated the synthetic temperature, optimum com-position and luminescent properties about the candidate phosphors. To construct the emission intensity library by VUV PL, we have synthesized 210 different compositional samples using a polymerized-complex method. Good luminescent samples were identified by X-ray diffraction method. $Ca_$\alpha$$G$d_{0.95-$\alpha$-$\beta$}Al_$\beta$O_$\delta$$ : Eu(0.02< $\alpha$+$\beta$ <0.04) phos-phors screened as a red phosphor have good color purity than commercial phosphor. In the candidate phosphors of CaGdAl$_3O_7$ : Tb, Ca$Al_{12}O_{19}$ : Tb, Gd$_4$Al$_2O_9$ : Tb, and Gd$_3Al_5O_{12}$ : Tb CaGdAl$_3O_7$ : Tb, and Ca$Al_{12}O_{19}$ : Tb have shorter decay time than commercial phosphor.

• Clinical and Experimental Pediatrics
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• v.61 no.11
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• pp.366-370
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• 2018

Purpose: Tuberculosis (TB) is one of the most important diseases that cause significant mortality and morbidity in young children. Data on TB transmission from an infected child are limited. Herein, we report a case of disseminated TB in a child and conducted a contact investigation among exposed individuals. Methods: A 4-year-old child without Bacille Calmette-$Gu{\acute{e}}rin$ vaccination was diagnosed as having culture-proven disseminated TB. The child initially presented with symptoms of inflammatory bowel disease, and nosocomial and kindergarten exposures were reported. The exposed individuals to the index case were divided into 3 groups, namely household, nosocomial, or kindergarten contacts. Evaluation was performed following the Korean guidelines for TB. Kindergarten contacts were further divided into close or casual contacts. Chest radiography and tuberculin skin test or interferon-gamma-releasing assay were performed for the contacts. Results: We examined 327 individuals (3 household, 10 nosocomial, and 314 kindergarten contacts), of whom 18 (5.5%), the brother of the index patient, and 17 kindergarten children were diagnosed as having latent TB infection (LTBI). LTBI diagnosis was more frequent in the children who had close kindergarten contact with the index case (17.1% vs. 4.4%, P=0.007). None of the cases had active TB. Conclusion: This is the first reported case of TB transmission among young children from a pediatric patient with disseminated TB in Korea. TB should be emphasized as a possible cause of chronic diarrhea and failure to thrive in children. A national TB control policy has been actively applied to identify Korean children with LTBI.

• Tuberculosis and Respiratory Diseases
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• v.78 no.4
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• pp.349-355
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• 2015

Background: The tuberculin skin test (TST) is the standard tool to diagnose latent tuberculosis infection (LTBI) in mass screening. The aim of this study is to find an optimal cut-off point of the TST+ rate within tuberculosis (TB) contacts to predict the active TB development among adolescents in school TB outbreaks. Methods: The Korean National Health Insurance Review and Assessment database was used to identify active TB development in relation to the initial TST (cut-off, 10 mm). The 7,475 contacts in 89 schools were divided into two groups: Incident TB group (43 schools) and no incident TB group (46 schools). LTBI treatment was initiated in 607 of the 1,761 TST+ contacts. The association with active TB progression was examined at different cut-off points of the TST+ rate. Results: The mean duration of follow-up was $3.9{\pm}0.9years$. Thirty-three contacts developed active TB during the 4,504 person-years among the TST+ contacts without LTBI treatment (n=1,154). The average TST+ rate for the incident TB group (n=43) and no incident TB group (n=46) were 31.0% and 15.5%, respectively. The TST+ rate per group was related with TB progression (odds ratio [OR], 1.025; 95% confidence interval [CI], 1.001-1.050; p=0.037). Based on the TST+ rate per group, active TB was best predicted at TST+ ${\geq}$ 16% (OR, 3.11; 95% CI, 1.29-7.51; area under curve, 0.64). Conclusion: Sixteen percent of the TST+ rate per group within the same grade students can be suggested as an optimal cut-off to predict active TB development in middle and high schools TB outbreaks.

• Economic and Environmental Geology
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• v.55 no.4
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• pp.407-419
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• 2022

Soil(vadose zone) gas compositions were measured for about 3 days to suggest a method for monitoring and interpreting soil gas data collected around wells from which methane(CH₄) is outflowing. The vadose zone gas samples were collected within 1 m around two test wells(TB2 and TB3) at Pohang and analyzed for CO₂, CH₄, N₂ and O₂ concentrations in situ. CO₂ flux was measured beside TB2. In addition, gas samples from well head in TB2 and atmospheric air samples were collected for comparison. Carbon isotopes of CO₂(δ¹³C_CO2) of samples collected on the last day of the study period were analyzed in the laboratory. The two test wells (TB2 and 3) were 12.7 m apart and only TB3 was cemented to the surface. According to the bio-geochemical process-based interpretation, the relationships between CO₂ and O₂, N₂, and N₂/O₂ of vadose zone gas were plotted between the lines of CH₄ oxidation and CO₂ dissolution. In addition, the CH₄ concentrations of gas samples from the wellhead of the uncemented well (TB2) were 5.2 times higher than the atmospheric CH₄ concentration. High CO₂ concentrations (average 1.148%) of vadose zone gas around TB2 seemed to be attributed to the oxidation of CH₄. On the other hand, the vadose zone CO₂ around the cemented well(TB3) showed a relatively low concentration(0.136%). This difference indicates that the vadose zone gas(including CO₂) around the CH₄ outflowing well were strongly affected by well completion(cementing). This study result can be used to establish strategies for environmental monitoring of soil around natural gas sites, and can be used to monitor leakage around injection and observation wells for CO₂ geological storage. In addition, the method of this study is useful for soil monitoring in natural gas storage and oil-contaminated sites.

• Tuberculosis and Respiratory Diseases
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• v.67 no.4
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• pp.331-337
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• 2009

Background: The whole-blood interferon-gamma release assay (QuantiFERON-TB Gold [QFT-G]: Cellestis, Carnegie, Victoria, Australia) has been studied primarily for the use of diagnosing active pulmonary tuberculosis (TB) or latent TB. In the present study, the usefulness of QFT-G was evaluated for the diagnosis of extra-pulmonary tuberculosis (EP-TB). Methods: From June 2006 to February 2009, we evaluated the usefulness of QFT-G in patients (n=65) suspected with EP-TB, retrospectively. The diagnostic sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of the QFT-G assay were analyzed. Results: EP-TB was diagnosed in 33 (51%) participants. The overall sensitivity, specificity, PPV, and NPV of the QFT-G assay for EP-TB were 78%, 79%, 81%, and 77%, respectively. Of the 33 with EP-TB, 14 (42%) were diagnosed with TB pleurisy, 7 (21%) with TB lymphadenitis, 7 (21%) with intestinal TB, and 5 (15%) with EP-TB in other sites. In subgroup analyses according by site of infection, the QFT-G showed 86% sensitivity, 64% specificity, and 78% NPV in TB pleurisy. On the other hand, the sensitivity, specificity, and NPV of the assay were 71%, 83% and 71%, respectively in TB lymphadenitis, and 86%, 100% and 88%, respectively in intestinal TB. Among the patients with suspected alternative site EP-TB, the sensitivity, specificity, and NPV of the assay were 50%, 80% and 67%, respectively. Conclusion: The QFT-G assay showed moderate diagnostic accuracy in EP-TB. However, negative QFT-G assay does not exclude EP-TB because of the low NPV of this assay.

• Elastomers and Composites
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• v.49 no.2
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• pp.103-109
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• 2014

Blends of emulsion SBR (E-SBR) and solution SBR (S-SBR) were prepared, and their microstructures (styrene, 1,2-unit, cis-1,4-unit, and trans-1,4-unit contents) were analyzed by Fourier transform infrared spectroscopy (FTIR) with transmittance mode. Method to measure absorbance by valley-to-valley baseline (TV) is objectively reasonable, but has a demerit which peak intensity of the cis-1,4-unit cannot be correctly measured. In order to obtain information for the four microstructures including cis-1,4-unit, measurement methods without correction (TM) and correction to 99% transmittance (TB) were compared to the TV method. Results obtained by the TB method were closer to those obtained by the TV one than those obtained by the TM. The microstructures were determined from the absorbances obtained by the TM and TB methods according to the ISO/FDIS 21561:2005(E). Variations of the styrene, 1,2-unit, and trans-1,4-unit contents with the blend ratio of E-SBR/S-SBR showed relatively good linearities, and there was no big difference between results obtained by the TM and TB methods. Variations of the cis-1,4-unit content with the blend ratio absolutely did not show linearities irrespective of the TM and TB methods.

• Journal of the Korean Ceramic Society
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• v.51 no.4
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• pp.260-264
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• 2014

We developed a novel double dopant bismuth oxide system with Tb and W. When Tb was doped as a single dopant, a Tb dopant concentration more than 20 mol% was required to stabilize bismuth oxides with a high conductivity cubic structure. High temperature XRD analysis of 25 mol% Tb-doped bismuth oxide (25TSB) confirmed that the cubic structure of 25TSB was retained from room temperature to $700^{\circ}C$ with increase in the lattice parameter. On the other hand, we achieved the stabilization of high temperature cubic phase with a total dopant concentration as low as ~12 mol% with 8 mol% Tb and 4 mol% W double dopants (8T4WSB). Moreover, the measured ionic conductivity of 10T5WSB was much higher than 25TSB, thus demonstrating the feasibility of the double dopant strategy to develop stabilized bismuth oxide systems with higher oxygen ion conductivity for the application of SOFC electrolytes at reduced temperature. In addition, we investigated the long-term stability of TSB and TWSB electrolytes.