• Economic and Environmental Geology
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• v.51 no.2
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• pp.87-97
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• 2018

The cesium (Cs) removal from the contaminated water system has been considered to be difficult because the cesium likes to exist as soluble phases such as ion and complexes than the solid in water system. Many researches have focused on developing the breakthrough adsorbent to increase the cesium removal efficiency in water. In this study, the laboratory scale experiments were performed to investigate the feasibility of the adsorption process using the bamboo charcoal for the Cs contaminated water system. The Cs removal efficiency of the bamboo charcoal were measured and the optimal adsorption conditions were determined by the adsorption batch experiments. Total 5 types of commercialized bamboo charcoals in Korea were used to identify their surface properties from SEM-EDS and XRD analyses and 3 types of bamboo charcoals having large specific surface areas were used for the adsorption batch experiment. The batch experiments to calculate the Cs removal efficiency were performed at conditions of various Cs concentration (0.01 - 10 mg/L), pH (3 - 11), temperature ($5-30^{\circ}C$), and adsorption time (10 - 120 min.). Experimental results were fitted to the Langmuir adsorption isotherm curve and their adsorption constants were determined to understand the adsorption properties of bamboo charcoal for Cs contaminated water system. From results of SEM-EDS analyses, the surfaces of bamboo charcoal particles were composed of typical fiber structures having various pores and dense lamella structures in supporting major adsorption spaces for Cs. From results of adsorption batch experiments, the Cs-133 removal efficiency of C type bamboo charcoal was the highest among those of 3 bamboo charcoal types and it was higher than 75 % (maximum of 82 %) even when the initial Cs concentration in water was lower than 1.0 mg/L, suggesting that the adsorption process using the bamboo charcoal has a great potential to remove Cs from the genuine Cs contaminated water, of which Cs concentration is low (< 1.0 mg/L) in general. The high Cs removal efficiency of bamboo charcoal was maintained in a relatively wide range of temperatures and pHs, supporting that the usage of the bamboo charcoal is feasible for various types of water. Experimental results were similar to the Langmuir adsorption model and the maximum amount of Cs adsorption (qm:mg/g) was 63.4 mg/g, which was higher than those of commercialized adsorbents used in previous studies. The surface coverage (${\theta}$) of bamboo charcoal was also maintained in low when the Cs concentration in water was < 1.0 mg/L, investigating that the Cs contaminated water can be remediated up with a small amount of bamboo charcoal.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.1
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• pp.37-45
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• 2012

Purpose: The change of alignment between RGP lens and cornea according to the lens design was investigated by comparing the areas of fluorescein pattern in central and peripheral regions analyzed by astigmatic degree and corneal type when spherical and aspherical RGP lenses fitted in alignment. Methods: The fluorescein patterns of 90 eyes (19-30 years, $25.12{\pm}3.52$) having with-the-rule astigmatism were analyzed after spherical and aspherical RGP lenses fitted in alignment. Then, their fluorescent areas in central and peripheral regions were calculated and compared for the quantitative evaluation. Results: The case showing concordant base curve between spherical and aspherical RGP lenses in alignment fitting was 72% however, the possibility to have same base curves between spherical and aspherical RGP lenses in alignment fitting was to be less in the case of symmetric bowtietyped cornea and high astigmatism. The fluorescent area in peripheral region of aspherical RGP lens in alignment fitting was smaller than it of spherical RGP lens. Peripheral fluorescent areas in both RGP lenses decreased according to the increase of astigmatic degree and peripheral area in symmetric bowtie-typed corea was smaller than round-typed cornea's peripheral area. In the case of same astigmatic degree, peripheral fluorescent area of aspherical RGP lens was smaller in both corneal types. Conclusions: The results above suggest the changing degree in the alignment between RGP lens and cornea can be varied according to lens design, corneal astigmatism and corneal type. Thus, the results obtained from the quantitative analysis of the alignment between lens design and cornea may be used as the basic information about the establishment of guidelines for RGP lens fitting, the development of proper lens design, and different tear volume in partial regions.

• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.29-33
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• 2006

Purpose : The aim of this study was to analyze the results and contributing factors of catch-up growth in very low birth weight infants(VLBWI) at the corrected age of 2 years. In addition, we looked for a relationship between the catch-up growth and the development by the bayley scales of infant development II(BSID II). Methods : A retrospective analysis by evaluating medical records was done for the 76 VLBWI whose follow-up was possible up to a corrected age of 2 years, out of the 114 who had been treated in the neonatal intensive care unit during the January of 2000 to December of 2001 at Samsung Cheil Hospital. Based on the Standard Korean Infant's Growth Curve, the catch-up growth group was defined over the 10th percentile of weight at 2 years as the corrected age and the failed catch-up growth group was defined under the 10th percentile. We investigated the clinical factors and courses of each group and compared the scores of the BSID II. Results : The catch-up growth group of the VLBWI was 51 infants and the failed catch-up growth group was 25 infants. In comparison with maternal clinical factors, use of antenatal steroids was significantly higher in the catch-up growth group. In comparisn with clinical factors and courses of VLBWI, two clinical factors were significantly different between the two groups : birth weight and intrauterine growth retardation(IUGR). Numbers of delayed development were increased in the failed catch-up growth group but statistically significant differences could not be observed. Conclusion : The catch-up growth of the VLBWI was affected by the use of antenatal steroids, birth weight and IUGR. No significant differences regarding neurodevelopmental outcome were observed between the catch-up and failed catch-up growth groups.

• Radiation Oncology Journal
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• v.26 no.3
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• pp.166-172
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• 2008

Purpose: The measurement of radiosensitivity of individuals is useful in radiation therapy. Unfortunately, the measurement of radiation survival using a clonogenic assay, which is the established standard, can be difficult and time consuming. The aim of this study is to compare radiosensitivity results obtained from the MTT and clonogenic assays, and to evaluate whether the MTT assay can be used on clinical specimens. Materials and Methods: HCT-8, LoVo, CT-26, and WiDr were the colon cancer cell lines used for this study. The clonogenic assay was performed to obtain the cell survival curves and surviving fractions at a dose of 2 Gy ($SF_2$) as the standard technique for radiosensitivity. Also, the MTT assay was performed for each of the cell lines (in vitro). To simulate clinical specimens, the cell lines were inoculated into nude mice, removed when the tumors reached 1 cm in diameter, and chopped. Next, the tumors were subjected to the same process involved with the MTT assay in vitro. The inhibition rates (IR) of 10 Gy or 20 Gy of irradiation for in vitro and ex vivo were calculated based on the optical density of the MTT assay, respectively. Results: According to $SF_2$ and the cell survival curve, the HCT-8 and WiDr cell lines were more resistant to radiation than LoVo and CT-26 (p<0.05). The IR was measured by in vitro. The MTT assay IR was 17.3%, 21%, 30% and 56.5% for the WiDr, HCT-8, LoVo and CT-26 cell lines, respectively. In addition, the IR measured ex vivo by the MTT assay was 23.5%, 26%, 38% and 53% in the HCT-8, WiDr, LoVo and CT-26 tumors, respectively. Conclusion: The radiosensitivity measured by the MTT assay was correlated with the measures obtained from the clonogenic assay. This result highlights the possibility that the MTT assay could be used in clinical specimens for individual radiosensitivity assays.

• Journal of the Korean Geographical Society
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• v.41 no.1 s.112
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• pp.106-120
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• 2006

Natural or man-made disaster has been expected to be one of the potential themes that can integrate human geography and physical geography. Typhoons like Rusa and Maemi caused great loss to insurance companies as well as public sectors. We have implemented a natural disaster management system for a private insurance company to produce better estimation of hazards from high wind as well as calculate vulnerability of damage. Climatic gauge sites and addresses of contract's objects were geo-coded and the pressure values along all the typhoon tracks were vectorized into line objects. National GIS topog raphic maps with scale of 1: 5,000 were updated into base maps and digital elevation model with 30 meter space and land cover maps were used for reflecting roughness of land to wind velocity. All the data are converted to grid coverage with $1km{\times}1km$. Vulnerability curve of Munich Re was ad opted, and preprocessor and postprocessor of wind velocity model was implemented. Overlapping the location of contracts on the grid value coverage can show the relative risk, with given scenario. The wind velocities calculated by the model were compared with observed value (average $R^2=0.68$). The calibration of wind speed models was done by dropping two climatic gauge data, which enhanced $R^2$ values. The comparison of calculated loss with actual historical loss of the insurance company showed both underestimation and overestimation. This system enables the company to have quantitative data for optimizing the re-insurance ratio, to have a plan to allocate enterprise resources and to upgrade the international creditability of the company. A flood model, storm surge model and flash flood model are being added, at last, combined disaster vulnerability will be calculated for a total disaster management system.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.3
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• pp.122-126
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• 2003

In this study, $Zn_{0.86}Mn_{0.14}$Te epilayer of 0.7 $\mu\textrm{m}$-thickness was grown on GaAs(100) substrate by using hot wallepitaxy. GaAs(100) substrate was removed from $Zn_{0.86}Mn_{0.14}$Teepilayer by the selective etching solution. The crystal structure and the lattice constant of only Z $n_{0.86}$ M $n_{0.14}$Te epilayer were investigated to be zincblende and 6.140 $\AA$ from X-ray diffraction pattern, respectively. Mn composition x of $Zn_{1-x}Mn_x$Te epilayer was found to be 0.14 using this lattice constant and Vegard's law. The crystal quality of the epilayer was confirmed to be very good due to 256 arcsec-full-width at half-maximum of the double crystal rocking curve. The absorption spectra from the transmission ones were obtained to measure the band gap energy of $Zn_{0.86}Mn_{0.14}$Te epilayer from 300 K to 10 K. With the decreasing temperature,. strong absorption regions in the absorption spectra were shifted to higher energy side and the absorption peak meaning the free exciton formation appeared near the absorption edge. The band gap energy values of $Zn_{0.86}Mn_{0.14}$Te epilayer at 0 K and 300 K were found to be almost 2.4947 eV and 2.330 eV from the temperature dependence of the free exciton peak position energy of $Zn_{0.86}Mn_{0.14}$Te epilayer, respectively. The free exciton peak position energy of $Zn_{0.86}Mn_{0.14}$Te epilayer without GaAs substrate was larger 15.4 meV than photoluminescence peak position energy at 10 K. This energy difference between two peaks was analysed to be Stokes shift.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.10 no.1
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• pp.115-123
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• 1990

The purpose of this study was to examine the uses of coal ash as a type of construction material. The methods of examination were chemical anlysis, soil laboratory test and the soil vibration test. Materials used were coal ash obtained as a by-product from 5 thermal power plants in Yongdong, Yongwol, Sochon(anthracite coal) and in Samchonpo and Honam (bituminous coal). Over 70% of the coal ash consisted of silica and alumina. The fly ash grain size showed a uniform distribution from fine-sand to silt, and that of the bottom ash showed from sand to gravel. The specific gravity and density of the coal ash were low. The long term strength increased gradually due to the self-setting property resulting from pozzolanic activity. The shear strength was higher than that of general soil. Cohesion and optimum moisture content of anthracite coal ash were higher than bituminous coal ash, whereas the maximum dry density was higher in bituminous coal ash. The coal ash dynamic Young's modulous curve range was similar to that of general soil. Of the results from the soil vibration test by car-running, the size relative acceleration level in the ash pond was higher than that of natural ground, but the damping ratio was lower than that of natural ground near the ash pond. The coal ash has more advantageous engineering properties than general soil with particles of the same size. For example, the California Bearing Ratio of the bottom ash at both Yongdong and Yongwol was 77~137%. Therefore we expect that if further study is done, coal ash can be used as a construction material when reclaiming seashore, construction embankments, road construction, making right-weight aggregate, or as a general construction material.

• Nuclear Medicine and Molecular Imaging
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• v.40 no.5
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• pp.249-256
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• 2006

Purpose: Although computed tomography (CT) is widely used for diagnosing liver metastasis from colorectal cancer, diagnostic accuracy of CT is not satisfactory. Magnetic resonance (MR) imaging and F-18 FDG PET has been reported to be superior to CT. However, studies on direct comparison of PET and MR are scarce. We compared the diagnostic accuracy of FDG PET and MR in detecting liver metastasis from colorectal cancer. Materials and Methods: Among 363 colorectal cancer patients who underwent F-18 FDG PET (ECAT, Siemens-CTI, Knoxville; Gemini, Philips, Milpitas, U.S.), 26 patients (M:F=17:9, age=$62{\pm}11$) underwent MR to evaluate suspicious metastatic liver lesions. Finally, 35 liver lesions detected by CT from 26 patients were enrolled for analysis. PET and MR results were compared with pathologic reports, clinical findings or follow-up results. Results: Of the 35 lesions, 18 lesions (51.4%) were diagnosed as liver metastases, while remaining 17 (48.6%) as benign. The sensitivity and the specificity of PET were 94.4% and 94.1%, respectively, compared to 100% and 82.4% for MR. MR and PET was concordant in 30 lesions (85.7%: 17 metastatic (94.4%) and 13 benign (76.5%) lesions. ROC curve analysis revealed maximal SUV of 3.1 as the optimum standard in differentiating metastatic from benign liver lesions (AUC=0.897, p<0.001, sensitivity 83.3%, specificity 94.1%). For small lesions less than 1 cm ln diameter (n=20), diagnostic accuracy of PET was comparable to that of MR. Conclusion: F-18 FDG PET showed good diagnostic performance in detecting liver metastasis from colorectal cancer, which was comparable to MR.

• Journal of Veterinary Clinics
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• v.29 no.3
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• pp.233-236
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• 2012

Cefquinome, a fourth generation cephalosporin, has been solely used for veterinary medicine and has a broad antibacterial spectrum against gram-negatives and gram-positives being very stable to ${\beta}$-lactamases. This study was conducted to evaluate the bioequivalence of two cefquinome 2.5% products in piglets. Plasma cefquinome concentrations were analyzed by liquid chromatography-mass spectrometry (LC/MS). Mean maximum concentration ($C_{max}$) of test product ($Cequus^{(R)}$) and reference product ($Cobactan^{(R)}$) were $4.34{\pm}0.58$ and $4.22{\pm}0.47{\mu}g/mL$, and mean area under the concentration time curve ($AUC_{0{\rightarrow}{\infty}}$) values were $10.43{\pm}1.96$ and $10.25{\pm}2.98{\mu}g{\cdot}h/mL$, respectively. The 90% confidence intervals for the ratio of $C_{max}$ (0.941-1.115), and $AUC_{0{\rightarrow}{\infty}}$ (0.927-1.172) values for the test and reference products were within the acceptable bioequivalence limit of 0.80-1.25. It is concluded that two commercial cefquinome injectable solutions are bioequivalent in their extent of drug absorption in piglets.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.14
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• pp.5839-5843
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• 2014

Objective: The Zhejiang Provincial Cancer Prevention and Control Office collected cancer registration data during 2000 to 2009 from 6 cancer registries in Zhejiang province of China in order to analyze the cancer incidence. Methods: Descriptive analysis included cancer incidence stratified by sex, age and cancer site group. The proportions and cumulative rates of 10 common cancers in different groups were also calculated. Chinese population census in 1982 and Segi's population were used for calculating age-standardized incidence rates. The log-linear model was used for fitting to calculate the incidence trends. Results: The 6 cancer registries in Zhejiang province in China covered a total of 60,087,888 person-years during 2000 to 2009 (males 30,445,904, females 29,641,984). The total number of new cancer cases were 163,104 (males 92,982, females 70,122). The morphology verified cases accounted for 69.7%, and the new cases verified only by information from death certification accounted for 1.23%. The crude incidence rate in Zhejiang cancer registration areas was $271.5/10^5$ during 2000 to 2009 (male $305.41/10^5$, female $236.58/10^5$), age-standardized incidence rates by Chinese standard population (ASIRC) and by world standard population (ASIRW) were $147.1/10^5$ and $188.2/10^5$, the cumulative incidence rate (aged from 0 to 74) being 21.7%. The crude incidence rate was $209.6/10^5$ in 2000, and it increased to $320.20/10^5$ in 2009 (52.8%), with an annual percent change (APC) of 4.51% (95% confidence interval, 3.25%-5.79%). Age-specific incidence rate of 80-84 age group was achieved at the highest point of the incidence curve. Overall with different age groups, the cancer incidences differed, the incidence of liver cancer being highest in 15-44 age group in males; the incidence of breast cancer was the highest in 15-64 age group in females; the incidences of lung cancer were the highest in both males and females over the age of 65 years. Conclusions: Lung cancer, digestive system malignancies and breast cancer are the most common cancers in Zhejiang province in China requiring an especial focus. The incidences of thyroid cancer, prostate cancer, cervical cancer and lymphoma have increased rapidly. Prevention and control measures should be implemented for these cancers.