• Journal of the Korean Society of Radiology
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• v.14 no.5
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• pp.563-575
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• 2020

The purpose of this study is to evaluate the activation characteristics that occur in a linear accelerator for container security inspection. In the computer simulation design, first, the targets consisted of a tungsten (Z=74) single material target and a tungsten (Z=74) and copper (Z=29) composite target. Second, the fan beam collimator was composed of a single material of lead (Z=82) and a composite material of tungsten (Z-74) and lead (Z=82) depending on the material. Final, the concrete in the room where the linear accelerator was located contained magnetite type and impurities. In the research method, first, the optical neutron flux was calculated using the MCNP6 code as a F4 Tally for the linear accelerator and structure. Second, the photoneutron flux calculated from the MCNP6 code was applied to FISPACT-II to evaluate the activation product. Final, the decommissioning evaluation was conducted through the specific activity of the activation product. As a result, first, it was the most common in photoneutron targets, followed by a collimator and a concrete 10 cm deep. Second, activation products were produced as by-products of W-181 in tungsten targets and collimator, and Co-60, Ni-63, Cs-134, Eu-152, Eu-154 nuclides in impurity-containing concrete. Final, it was found that the tungsten target satisfies the permissible concentration for self-disposal after 90 days upon decommissioning. These results could be confirmed that the photoneutron yield and degree of activation at 9 MeV energy were insignificant. However, it is thought that W-181 generated from the tungsten target and collimator of the linear accelerator may affect the exposure when disassembled for repair. Therefore, this study presents basic data on the management of activated parts of a linear accelerator for container security inspection. In addition, When decommissioning the linear accelerator for container security inspection, it is expected that it can be used to prove the standard that permissible concentration of self-disposal.

• Korean Journal of Soil Science and Fertilizer
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• v.37 no.4
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• pp.220-227
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• 2004

Phosphorus desorption study is essential to understanding P behavior in agricultural and environmental soils because phosphorus is considered as two different aspects, a plant nutrient versus an environmental contaminant. This study was conducted to determine soil P buffering power related to P desorption quantity intensity (Q/I) parameters, $Q_{max}$(an index of P release capacity) and $l_0$(an index of the intensity factor), and to investigate the characteristics of relationship between the P desorption Q/I parameters and the soil properties. Soil samples were prepared with treatments of 0 and $100mg\;P\;kg^{-1}$ applied as $KH_2PO_4$ solution. The P desorption Q/I curves were obtained by a procedure using anion exchange resin beads and described by an empirical equation ($Q=aI^{-1}+bln(I+1)+c$). The P desorption Q/I curves for the high available P (${\g}20mg\;kg^{-1}$ of Olsen P) soils were characteristic concave trends with or without soil P enrichment, whereas for the low available P (${\lt}20mg\;kg^{-1}$ of Olsen P) soils, the anticipated Q/I concave curves could not be obtained without a proper amount of P addition. When the soils were enriched in phosphates, the values of desorbed solid phase labile P and solution P, such as $Q_{max}$ and $I_0$ respectively, were increased, but the ratio of $Q_{max}$ versus $I_0$ was decreased. Thus, the slope of desorption Q/I curve represented as phosphorus buffering power, $|BP_0|$, is decreased. The $|BP_0|$ values of the high available P soils ranged between 48 and $61L\;kg^{-1}$ in the P untreated samples and between 18 and $44L\;kg^{-1}$ in the P enriched samples. Overall $|BP_0|$ values of both low and high available P soils treated with $l00mg\;P\;kg^{-1}$ ranged between 14 and $79L\;kg^{-1}$. The $Q_{max}$, values ranged between 71.4 and $173.1mg\;P\;kg^{-1}$, and the lo values ranged between 0.98 and $3.82mg\;P\;L^{-1}$ in the P enriched soils. The $Q_{max}$ and $I_0$ values that control the P buffering power may be not specifically related to a specific soil property, but those values were complicatedly related to soil pH, clay content, soil organic matter content, and lime. Also, phosphorus release activity, however, markedly depended on the desorbability of the applied P as well as the native labile P.

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.509-518
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• 1993

Background: By amplifying small amount of DNA, polymerase chain reaction (PCR) can be used for the detection of very small amount of microbial agent, and may be especially useful in certain cases which are difficult to be diagnosed microbiologically or serologically. Tuberculous pleurisy is a disease that can be diagnosed in only 70% of cases by conventional diagnostic tools, and PCR would be a very rapid, easy, and sensitive diagnostic method. Method: The specificity and sensitivity of PCR to detect Mycobacterium tuberculosis DNA were evaluated using various strains of Mycobacteria. To evaluate the diagnostic usefulness of PCR in tuberculous pleurisy, we used PCR to detect Mycobacterium tuberculosis DNA in pleural fluid. The amplification target was 123 base pair DNA, a part of IS6110 fragment, 10~16 copies of which are known to exist per genome. The diagnostic yield of PCR was compared with conventional methods, including pleural fluid adenosine deaminase (ADA) activity. Also, the significance of PCR in undiagnosed pleural effusion was evaluated prospectively with antituberculosis treatment. Results: 1) Using cultured Mycobacterium tuberculosis and other strains, PCR could detect upto 1 fg DNA and specific for only Mycobacterium tuberculosis and Mycobacterium bovis. 2) Using pleural effusions of proven tuberculosis cases, the sensitivity of PCR was 80.0% (16/20), and the specificity 95.0% (19/20). 3) Among 13 undiagnosed, but suspected tuberculous effusion, the positive rate was 60% in 10 improved cases after antituberculosis medications, and 0% in 3 cases of proven malignancy later. 4) Adenosine deaminase level of proven and clinically diagnosed tuberculous pleurisy patients was significantly higher than that of excluded patients, and correlated well with PCR results. Conclusion: We can conclude that PCR detection of Mycobacterium tuberculosis in pleural effusion has acceptable sensitivity and specificity, and could be an additional diagnostic tool for the diagnosis of tuberculous pleurisy.

• The Journal of Korean Medicine
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• v.31 no.1
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• pp.130-137
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• 2010

Objectives: So far it has been reported that acupuncture increases cerebral blood supply and stimulates the functional activity of brain nerve cells. Previous studies have demonstrated that frequently used electro-acupuncture (EA) therapies for stroke increased regional cerebral blood flow (rCBF) in normal volunteers. Though ST 36-ST 41 EA is another prevailing therapy for stroke, there had been no report about its effect on rCBF. This study was to evaluate the effect of ST 36-ST 41 EA on rCBF in normal volunteers using single photon emission computed tomography (SPECT) and statistical parametric mapping (SPM). Methods: In the resting state, $^{99m}Tc$-ECD brain SPECT scans were performed on 10 normal volunteers (5 males, 5 female, mean age $23.6{\pm}0.5$ years). On the other study day, 7 days after the resting examination, 15 minutesEA were applied at ST 36 and ST 41 on the right side of the subjects. Immediately after ST36-ST41 EA, the second SPECT images were obtained in the same manner as the resting state. Significant increases and decreases of rCBF after EA were estimated by comparing their SPECT images with those of the resting state using paired t statistics at every voxel, which were analyzed by SPM with a threshold of p = 0.01, uncorrected (extent threshold: k=100 voxels). Results: EA applied at the right ST36-ST41 significantly increased rCBF in the right inferior parietal lobule (Brodmann area [BA] 40), right retrosubicular area (BA 48), left inferior parietal lobule (BA 40), left middle temporal gyrus (BA 21), left fusiform gyrus (BA 37), left inferior parietal lobule (BA 39), left inferior temporal gyrus (BA 20), and left somatosensory association cortex (BA 7). However, right ST36-ST41 EA significantly decreased rCBF in the right parahippocampal gyrus (BA 35), right cerebellum, left frontopolar area (BA 10), left orbitofrontal area (BA 11), left dorsolateral prefrontal cortex (BA 9), and left dorsal anterior cingulate cortex (BA 32). Conclusions: These results demonstrate that rightST36-ST41 EA increased rCBF prominently in both inferior parietal lobule (BA 40) and right retrosubicular area (BA 48), which suggest that there be correlation between specific EA and corresponding rCBF.

• Economic and Environmental Geology
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• v.43 no.2
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• pp.109-121
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• 2010

The bioleaching experiment under $42^{\circ}C$ was effectively carried out to leach the more valuable element ions from the pyrite in the Gangyang mine waste. Bacteria can survive at this temperature, as indigenous acidophilic bacteria were collected in the Hatchobaru acidic hot spring, in Japan. To enhance the bacterial activity, yeast extract was added to the pyrite-leaching medium. The indigenous acidophilic bacteria appeared to be rod-shaped in the growth-medium which contained elemental sulfur and yeast extract. The rod-shaped bacteria ($0.7\times2.6\;{\mu}m$, $0.6\times7\;{\mu}m$, $0.8\times5\;{\mu}m$ and $0.7\times8.4\;{\mu}m$) were attached to the pyrite surface. The colonies of the rod-shaped bacteria were selectively attached to the surroundings of a hexagonal cavity and the inner wall of the hexagonal cavity, which developed on a pyrite surface. Filament-shaped bacteria ranging from $4.92\;{\mu}m$ to $10.0\;{\mu}m$ in length were subsequently attached to the surrounding cracks and inner wall of the cracks on the pyrite surface. In the XRD analysis, the intensity of (111), (311), (222) and (320) plane on the bacteria pyrite sample relatively decreased in plane on the control pyrite sample, whereas the intensity of (200), (210) and (211) increased in these samples. The microbiological leaching content of Fe ions was found to be 3.4 times higher than that of the chemical leaching content. As for the Zn, microbiological leaching content, it was 2 times higher than the chemical leaching content. The results of XRD analysis for the bioleaching of pyrite indicated that the indigenous acidophilic bacteria are selectively attacked on the pyrite specific plane. It is expected that the more valuable element ions can be leached out from the mine waste, if the temperature is increased in future bioleaching experiments.

• Proceedings of the Korean Society for Applied Microbiology Conference
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• 2005.06a
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• pp.154-164
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• 2005

Saccharomyces cerevisiae KNU5377 is a thermotolerant strain, which can ferment ethanol from wasted papers and starch at 40$^{\circ}C$ with the almost same rate as at 30$^{\circ}C$. This strain showed alcohol fermentation ability to convert wasted papers 200 g (w/v) to ethanol 8.4% (v/v) at 40$^{\circ}C$, meaning that 8.4% ethanol is acceptable enough to ferment in the industrial economy. As well, all kinds of starch that are using in the industry were converted into ethanol at 40$^{\circ}C$ with the almost same rate as at 30$^{\circ}C$. Hyperthermic cell killing kinetics and differential scanning calorimetry (DSC) revealed that exponentially growing cells of this yeast strain KNU5377 were more thermotolerant than those of S. cerevisiae ATCC24858 used as a control. This intrinsic thermotolernace did not result from the stability of entire cellular components but possibly from that of a particular target. Heat shock induced similar results in whole cell DSC profiles of both strains and the accumulation of trehalose in the cells of both strains, but the trehalose contents in the strain KNU5377 were 2.6 fold higher than that in the control strain. On the contrary to the trehalose level, the neutral trehalase activity in the KNU5377 cells was not changed after the heat shock. This result made a conclusion that though the trehalose may stabilize cellular components, the surplus of trehalose in KNU5377 strain was not essential for stabilization of whole cellular components. A constitutively thermotolerant yeast, S. cerevisiae KNU5377, was compared with a relatively thermosensitive control, S. cerevisiae ATCC24858, by assaying the fluidity and proton ATPase on the plasma membrane. Anisotropic values (r) of both strains were slightly increased by elevating the incubation temperatures from 25$^{\circ}C$ to 37$^{\circ}C$ when they were aerobically cultured for 12 hours in the YPD media, implying the membrane fluidity was decreased. While the temperature was elevated up to 40$^{\circ}C$, the fluidity was not changed in the KNU5377 cell, but rather increased in the control. This result implies that the plasma membrane of the KNU5377 cell can be characterized into the more stabilized state than control. Besides, heat shock decreased the fluidity in the control strain, but not in the KNU5377 strain. This means also there's a stabilization of the plasma membrane in the KNU5377 cell. Furthermore, the proton ATPase assay indicated the KNU5377 cell kept a relatively more stabilized glucose metabolism at high temperature than the control cell. Therefore, the results were concluded that the stabilization of plasma membrane and growth at high temperature for the KNU5377 cell. Genome wide transcription analysis showed that the heat shock responses were very complex and combinatory in the KNU5377 cell. Induced by the heat shock, a number of genes were related with the ubiquitin mediated proteolysis, metallothionein (prevent ROS production from copper), hsp27 (88-fold induced remarkably, preventing the protein aggregation and denaturation), oxidative stress response (to remove the hydrogen peroxide), and etc.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.431-440
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• 2005

Local K-index is an indicator representing local geomagnetic activity in every 3 hour. For estimation of the local K-index, a reasonable determination of solar quiet curve (undisturbed daily variation of geomagnetic field) is quiet essential. To derive the solar quiet curve, the FMI method, which is one of representative algorithms, uses horizontal components (H and D) of 3 days magnetometer data from the previous day to the next day for a specific day. However, this method is not applicable to real time forecast since it always requires the next day data. In this study, we have devised a new method to estimate local K-index in near real-time by modifying the FMI method. The new method selects a recent quiet day whose $K_p$ indices, reported by NOAA/SEC are all lower than 3, and replace the previous day and the next day data by the recent quiet day data. We estimated 2,672 local K indices from Gyeongzu magnetometer in 2003, and then compared the indices with those from the conventional FMI method. We also compared the K indices with those from Kakioka observatory. As a result, we found that (1) K indices from the new method are nearly consistent with those of the conventional FMI method with a very high correlation (R=0.96); (2) onr local K indices also have a relatively high correlation (R=0.81) with those from Kakioka station. Our results show that the new method can be used for near real-time estimation of local K indices from Gyeongzu magnetometer.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2003.10a
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• pp.111-124
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• 2003

Processes that cause immobilization of contaminants in soil are of great environmental importance because they may lead to a considerable reduction in the bioavailability of contaminants and they may restrict their leaching into groundwater. Previous investigations demonstrated that pollutants can be bound to soil constituents by either chemical or physical interactions. From an environmental point of view, chemical interactions are preferred, because they frequently lead to the formation of strong covalent bonds that are difficult to disrupt by microbial activity or chemical treatments. Humic substances resulting from lignin decomposition appear to be the major binding ligands involved in the incorporation of contaminants into the soil matrix through stable chemical linkages. Chemical bonds may be formed through oxidative coupling reactions catalyzed either biologically by polyphenol oxidases and peroxidases, or abiotically by certain clays and metal oxides. These naturally occurring processes are believed to result in the detoxification of contaminants. While indigenous enzymes are usually not likely to provide satisfactory decontamination of polluted sites, amending soil with enzymes derived from specific microbial cultures or plant materials may enhance incorporation processes. The catalytic effect of enzymes was evaluated by determining the extent of contaminants binding to humic material, and - whenever possible - by structural analyses of the resulting complexes. Previous research on xenobiotic immobilization was mostly based on the application of $^{14}$ C-labeled contaminants and radiocounting. Several recent studies demonstrated, however, that the evaluation of binding can be better achieved by applying $^{13}$ C-, $^{15}$ N- or $^{19}$ F-labeled xenobiotics in combination with $^{13}$ C-, $^{15}$ N- or $^{19}$ F-NMR spectroscopy. The rationale behind the NMR approach was that any binding-related modification in the initial arrangement of the labeled atoms automatically induced changes in the position of the corresponding signals in the NMR spectra. The delocalization of the signals exhibited a high degree of specificity, indicating whether or not covalent binding had occurred and, if so, what type of covalent bond had been formed. The results obtained confirmed the view that binding of contaminants to soil organic matter has important environmental consequences. In particular, now it is more evident than ever that as a result of binding, (a) the amount of contaminants available to interact with the biota is reduced; (b) the complexed products are less toxic than their parent compounds; and (c) groundwater pollution is reduced because of restricted contaminant mobility.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 1994.07a
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• pp.184-215
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• 1994

The Hydrogeologic data of 455 water wells comprising geologic and aquifer test were analyzed to determine hydrogeoloic characteristics of Cheju island. The groundwater of Cheju island is occurred in unconsolidated pyroclastic deposits interbedded in highly jointed basaltic and andesic rocks as high level, basal and parabasal types order unconfined condition. The average transmissivity and specific yield of the aquifer are at about 29,300m$^2$/day and 0.12 respectively. The total storage of groundwater is estimated about 44 billion cubic meters(m$^3$). Average annual precipitation is about 3390 million m$^3$ among which average recharge amount is estimated 1494 million m$^3$ equivalent 44.1% of annual precipitation with 638 million m$^3$ of runoff and 1256 million m$^3$ of evapotranspiration. Based on groundwater budget analysis, the sustainable yield is about 620 million m$^3$(41% of annual recharge)and rest of it is discharging into the sea. The geologic logs of recently drilled thermal water wens indicate that very low-permeable marine sediments(Sehwa-ri formation) composed of loosely cemented sandy sat derived from mainly volcanic ashes, at the 1st stage volcanic activity of the area was situated at the 120$\pm$68m below sea level. And also the other low-permeable sedimentary rock called Segipo-formation which is deemed younger than former marine sediment is occured at the area covering north-west and western part of Cheju at the $\pm$70m below sea level. If these impermeable beds are distributed as a basal formation of fresh water zone of Cheju, most of groundwater in Cheju will be para-basal type. These formations will be one of the most important hydrogeologic boundary and groundwater occurences in the area.

• Journal of Chest Surgery
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• v.36 no.1
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• pp.7-14
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• 2003

Cyclin I plays a pivotal role in the regulation of G1-S transition and could consequently be a deregulated molecule in tumors. The activity of the cdk2-cyclin E complex is increased by degradation of cdk inhibitor p27kip1. Little is known about the expression and prognostic significance of cyclin E and p27 in non-small cell lung cancer(NSCLC). Material and Method: The expression of cyclin E and p27 in eighty-one cases of resected stage I NSCLC tissues and its relation to major clinico-pathological factors, including histology, differentiation, size of tumor, pleural invasion and survival rate were studied and analyzed. Immunohistochemical analysis with monoclonal antibodies specific for cyclin E and p27 were performed by ABC method. Result: Expression rates of cyclin E and p27 in stage I NSCLC tissues were 29.6% and 28.4% respectively. Cyclin E was expressed higher in cases of pleural invasion(p=0.04), and p27 was expressed higher in diameter of tumor less than 3cm(p=0.015). The 5-years survival rate was lower in cases of Positive expression of cyclin E than in cases of negative expression of cyclin E(44.4% vs 68.2%, p=0.015), and the 5-years survival rate was 72.2% in positive expression of p27 and 56.2% in negative expression of p27(p=0.09). The 5-years survival rate was higher in negative expression of cyclin E and positive expression of p27 than in cases of positive expression of cyclin I and negative expression of p27 (73.5% vs 36.3%, p=0.0029). In multivariate analysis, expression of cyclin I was an unfavorable prognostic factor(RR=3.578, p=0.006) and p27 was a favorable prognostic factor(RR=0.183, p=0.019) independently. Conclusion: Cyclin E and p27 may play a pivotal role for the biological behavior of stage I NSCLC, so that the expressions of cyclin I and p27 nay be new prognostic markers.