• Journal of the Korean Ceramic Society
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• v.53 no.2
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• pp.194-199
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• 2016

Presently, for the cement industry, studies that seek to reduce $CO_2$, because of the development of the plastic industry and demand for reduction of energy use, have been actively conducted among them, studies attempting to use Gamma-$C_2S({\gamma}-C_2S)$ to fix $CO_2$ have been actively conducted. The ${\gamma}-C_2S$ compound has an important function in reacting to $CO_2$ and stiffening through carbonatization in the air. The ${\gamma}-C_2S$ compound, reacting to $CO_2$ in the air, generates $CaCO_2$ within the pore structure of cement materials and densifies the pore structure this leads to an improvement of the durability and to the characteristic of resistance against neutralization. Therefore, in this experiment, in order to synthesize ${\gamma}-C_2S$, limestone sludge and waste foundry sands are used these materials are plasticized for 30 or 60 minutes at $1450^{\circ}C$, and are prevented from being cooled in the temperature range of $30{\sim}1000^{\circ}C$ when they are about to be cooled. XRD analysis and XRF analysis are used to determine the effects of this process on ${\gamma}-C_2S$ synthesization, the temperature at which a thing is plasticized, and the conditions for cooling that obtain in the plasticized clinker also, in order to confirm the $CO_2$ capture function, analysis of the major hydration products is conducted through an analysis of carbonatization depth and compressive strength, and through MIP analysis and XRD Rietveld analysis. As a result of these analyses, it is found that when ${\gamma}-C_2S$ was synthesized, the clinker that was plasticized at $1450^{\circ}C$ for one hour demonstrated the highest yield rate the sample with which the ${\gamma}-C_2S$ was mixed generated $CaCO_3$ when it reacted with $CO_2$ therefore, carbonatization depth and porosity were reduced, and the compressive strength was increased.

• Journal of Gastric Cancer
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• v.6 no.4
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• pp.250-256
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• 2006

Purpose: Recently, interest in peroxisome-proliferator-activated receptors (PPAR) has increased, although clinical studies of the effect of $PPAR-{\gamma}$ expression on gastric cancer have not been reported yet. In this study, we investigated the role of $PPAR-{\gamma}$ expression in gastric cancer patients. Materials and Methods: One hundred twenty-eight (128) samples of both gastric cancer and normal tissues were obtained from 128 patients who had undergone at a curative gastrectomy at Seoul Medical Center from Jan. 2001 to Dec. 2005. $PPAR-{\gamma}$ expression was determined by using immunohistochemical staining, and the results were analyzed. The statistical analysis was based on clinicopathological findings and the differences in survival rates. Results: The mean age of the patients was 6n, and the male : female ratio was 1.9 : 1. $PPAR-{\gamma}$ expression was significantly higher in cancer tissues than in normal tissue (81.3% vs. 57.0%, p<0.001). There was insignificant difference between well and moderately differentiated types and poorly differentiated types in terms of the expression of $PPAR-{\gamma}$ (87.0% vs. 74.6%, P=0.074). In the univariate analysis the survival rate was significantly increased when $PPAR-{\gamma}$ was expressed in normal tissue (P=0.003). In the multivariate analysis, only the UICC TNM staging had significance related to the survival rate. Conclusion: The rate of $PPAR-{\gamma}$ expression was higher in cancer tissue than it was in normal tissue from gastric cancer patients. In the univariate analysis, $PPAR-{\gamma}$ expression in normal tissue had significance with respect to survival, but the multivariate analysis showed no such significance. Thus, we should further evaluate more cases to determine whether or not such a significance exists.

• The Korean Journal of Nuclear Medicine Technology
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• v.27 no.1
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• pp.36-41
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• 2023

Purpose The long-term trend of extrinsic uniformity by type of gamma camera was analyzed, and the factors affecting uniformity were investigated. Based on this, the purpose was to predict the life of the gamma camera, pay attention to factors that affect uniformity, and obtain better quality images. Materials and methods Four of the gamma cameras in operation at a senior general hospital in Seoul were selected and the trend of extrinsic uniformity from the first operation date to the present was analyzed. In order to minimize various factors affecting uniformity, a detailed analysis was conducted by calculating the monthly and annual average of the uniformity values. Results Two Symbia E gamma cameras from SIEMENS, one Symbia Evo Excel gamma camera, and one Symbia Intevo16 gamma camera were selected and analyzed. The uniformity of Symbia E₁ (2012 warehousing) changed unevenly, and the uniformity of Symbia E₂ (2014 warehousing) changed according to the replacement cycle of ⁵⁷Co sheet sources. The uniformity of Symbia Evo Excel (received in 2017) and Symbia Intevo 16 (received in 2017) was constant compared to Symbia E. Conclusion The extrinsic uniformity of the gamma camera gradually increased over time. However, there was a difference in uniformity for each type of gamma camera, and there was a change in uniformity in which the cause could not be accurately identified. In order to improve the quality of the image, it is necessary to periodically check changes in uniformity and minimize factors that affect uniformity.

• Journal of Food Hygiene and Safety
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• v.21 no.3
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• pp.171-180
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• 2006

Peroxisome proliferatorr-activated receptor-gamma $(PPAR{\gamma})$ must form a heterodimer with the retinoid-X receptor (RXR) to bind DNA, and its transcriptional activity is thought to be maximized by ligands specific for either receptor. Activated $(PPAR{\gamma})$ and $(PPAR{\gamma})$ ligands may influence tumor growth through regulation of the tumor suppressor PTEN. Our aim in this study was to determine whether co-stimulation with the $(PPAR{\gamma})$ ligand, ciglitazone, and RXR ligand can synergistically upregulate PTEN in human acute promyelocytic leukemia (APL) cells and consequently potentate the inhibition of cell growth and cell cycle progression of these cells. Human leukemia cell line, HL-60 cells were exposed to all-trans-retinol and ciglutazone. The PTEN expression was measured as the level of PTEN mRNA expression by RT-PCR and as the level of PTEN expression by western blot analysis. Cell cycle analysis was carried out by a propidium iodide (PI) staining method and analyzed with a FACScan. The $(PPAR{\gamma})$ ligand, ciglitazone, and the RXR ligand, retinoic acid, upregulated PTEN expression by HL-60 cells in time- and dose-dependent manners, respectively. This was significantly enhanced by a combination of both ciglitazone and retinoic acid. Moreover, these compounds synergistically induced arrests of both cell growth and the $G_l$ phase of the cell cycle. Thus, the activation of the $(PPAR{\gamma})$:RXR heterodimer may represent a regulatory pathway for human leukemia cells and there may be important roles for $(PPAR{\gamma})$ and RXR ligands in prophylactic and therapeutic approaches fur controlling leukemia through the upregulation of PTEN.

• Nuclear Engineering and Technology
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• v.55 no.7
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• pp.2366-2372
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• 2023

Are borate and silicate glasses suitable for working as shieling materials against fast neutrons? To correctly answer the above question, some silicate, and borate-based glasses were fabricated and irradiated with various doses of fast neutrons varied between 1.73 and 12.10 MGy. The color and hardness of the fabricated glasses were affected by the fast neutron fluence where the transparent glasses turned colored as well as the hardness of the fabricated glasses was decreased. The gamma-ray spectrometric analysis shows a high activity concentration produced in the barium borate glasses due to the formation of radioisotopes Ba-131 and Ba-133 reaches to 5.92E+05 Bq and 4.25E+03 Bq, respectively for sample Cd-5 Batch 3. Additionally, the gamma-ray spectrometric analysis for the sodium silicate glasses shows low activity concentrations emitted from isotopes formed due to the activation of Y₂O₃-associated impurities. These activities are low compared to that emitted by barium borate-based glasses.

• Communications for Statistical Applications and Methods
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• v.5 no.3
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• pp.733-742
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• 1998

For industrial and medical lifetime data, the generalized log-gamma regression model is considered. Then the Bayesian analysis for the generalized log-gamma regression with censored data are explained and following the data augmentation (Tanner and Wang; 1987), the censored data is replaced by simulated data. To overcome the complicated Bayesian computation, Makov Chain Monte Carlo (MCMC) method is employed. Then some modified algorithms are proposed to implement MCMC. Finally, one example is presented.

• Nuclear Engineering and Technology
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• v.35 no.4
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• pp.347-355
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• 2003

The \gamma-ray spectrometer of the PGAA (Prompt Gamma Activation Analysis) facility constructed at HANARO of the Korea Atomic Energy Research Institute was upgraded to the multi-mode spectrometer including the single mode, the Compton suppression mode and the pair mode. The performance of the spectrometer was tested and summarized. The background count rate and the uncertainty of the detection efficiency were reduced greatly in comparison with those before the new installation.

• Journal of Life Science
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• v.21 no.5
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• pp.621-626
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• 2011

AMP-activated protein kinase (AMPK), a heterotrimeric complex comprising a catalytic ${\alpha}$ subunit and regulatory ${\beta}$ and ${\gamma}$ subunits, has been primarily studied as a major metabolic regulator in various organisms, but recent genetic studies discover its novel physiological functions. The first animal model with no functional AMPK ${\gamma}$ subunit gene was generated by using Drosophila genetics. AMPK ${\gamma}$ flies demonstrated lethality with severe defects in cuticle formation. Further histological analysis found that deletion of AMPK ${\gamma}$ causes severe defects in cell polarity in embryo epithelia. The phosphorylation of nonmuscle myosin regulatory light chain (MRLC), a critical regulator of epithelial cell polarity, was also diminished in AMPK ${\gamma}$ embryo epithelia. These defects in AMPK ${\gamma}$ mutant epithelia were successfully restored by over-expression of AMPK ${\gamma}$. Collectively, these results suggested that AMPK ${\gamma}$ is a critical cell polarity regulator in metazoan development.

• Journal of Radiation Protection and Research
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• v.23 no.4
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• pp.211-218
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• 1998

The distributional effects of radioactive materials on external gamma exposure have been analyzed. An approximate method for estimating external gamma dose given from an arbitrary distribution of radioactive material has been developed. The minimum gamma exposure given from a point source is shown at 0.07 MeV if the source to receptor distance is shorter than 10 m. But if the receptor to point source distance is longer than 20 m, gamma exposure rate increases monotonously according to the average gamma energy. For the analysis of the effects of volume source, we estimated the gamma dose given from different size of hemisphere in which radioactive materials are distributed uniformly. When the radius of hemisphere is longer than 40 m, external gamma dose rate increases monotonously. The gamma dose rate given from the radioactive materials deposited on the ground shows the minimum value at 0.07 MeV in any case. The analysis shows that external gamma exposure is strongly dependent on the distribution of radioactive materials in the environment and gamma energy.

• The Korean Journal of Applied Statistics
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• v.28 no.2
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• pp.221-230
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• 2015

Traditionally, sib-pair linkage analysis with repeated measures has employed linear mixed models, but it suffers from the lack of power to find genetic marker loci associated with a phenotype of interest. In this paper, we use a gamma mixed model to improve sib-pair linkage analysis and compare it with a linear mixed model in terms of power and Type I error. We illustrate that the use of gamma mixed model can achieve higher power than linear mixed model with Genetic Analysis Workshop 13 data.