Domestic commercial low- and intermediate-level radioactive waste storage containers are manufactured using 1.2 mm thick cold-rolled steel sheets, and the outer surface is coated with a thin layer of primer of 10~36 μm. However, the outer surface of the primer of the container may be damaged due to physical friction, such as acceleration, resonance, and vibration during transportation. As a result, exposed steel surfaces undergo accelerated corrosion, reducing the overall durability of the container. The integrity of storage containers is directly related to the safety of workers. Therefore, the development of storage containers with enhanced durability is necessary. This paper provides an analysis of mechanical properties related to the durability of WC (tungsten carbide)-based coating materials for developing low- and intermediate-level radioactive waste storage containers. Three different WC-based coating specimens with varied composition ratios were prepared using HVOF (high-velocity oxy-fuel) technique. These different specimens (namely WC-85, WC-73, and WC-66) were uniformly deposited on cold-rolled steel surfaces ensuring a constant thickness of 250 μm. In this work, the mechanical properties of the three different WCbased coaitng materials evaluated from the viewpoints of microstructure, hardness, adheision force between substrate and coating material, and wear resistance. The cross-sectional SEM-EDS (Scanning Electron Microscope-Energy Dispersive X-ray Spectroscopy) images revealed that elements W (tungsten), C (carbon), Ni (nickel), and Cr (chromium) were uniformly distributed within the each coating layers which was approximately 250 μm thick. The average hardness values of HWC-85 and HWC-73 were found to be 1,091 Hv (Vickers Hardness) and 1,083 Hv, respectively, while the HWC-66 exhibited relatively lower hardness value of 883 Hv. This indicates that a higher WC content results in increased hardness. Adhesion force between and substrates and coating materials exceeded 60 MPa for all specimens, however, there were no significant differences observed based on the tungsten carbide content. Furthermore, a taber-type abrasion tester was used for conducting abrasion resistance tests under specific conditions including an H-18 load weight at 1,000 g with rotational speed set at 60 RPM. The abrasion resistance tests were performed under ambient temperatures (RT: 23±2°C) as well as relative humidity levels (RH: 50±10%). Currently, the ongoing abrasion resistance tests will include some results in this study.

This study focuses on the development of coatings designed for storage containers used in the management of radioactive waste. The primary objective is to enhance the shielding performance of these containers against either gamma or neutron radiation. Shielding against these types of radiation is essential to ensure the safety of personnel and the environment. In this study, tungsten and boron cabide coating specimens were manufactured using the HVOF (High-Velocity Oxy Fuel) technuqe. These coatings act as an additional layer of protection for the storage containers, effectively absorbing and attenuating gamma and neutron radiation. The fabricated tungsten and boron carbide coating specimens were evaluated using two different testing methods. The first experiment evaluates the effectiveness of a radiation shielding coating on cold-rolled steel surfaces, achieved by applying a mixture of WC (Tungsten Carbide) powders. WC-based coating specimens, featuring different ratios, were prepared and preliminarily assessed for their radiation shielding capabilities. In the gamma-ray shielding test, Cs-137 was utilized as the radiation source. The coating thickness remained constant at 250 μm. Based on the test results, the attenuation ratio and shielding rate for each coated specimen were calculated. It was observed that the gammaray shielding rate exhibited relatively higher shielding performance as the WC content increased. This observation aligns with our findings from the gamma-ray shielding test and underscores the potential benefits of increasing the tungsten content in the coating. In the second experiment, a neutron shielding material was created by applying a 100 μm-thick layer of B4C (Boron Carbide) onto 316SS. The thermal neutron (AmBe) shielding test results demonstrated an approximate shielding rate of 27%. The thermal neutron shielding rate was confirmed to exceed 99.9% in the 1.5 cm thick SiC+B4C bulk plate. This indicates a significant reduction in required volume. This study establishes that these coatings enhance the gamma-ray and neutron shielding effectiveness of storage containers designed for managing radioactive waste. In the future, we plan to conduct a comparative evaluation of the radiation shielding properties to optimize the coating conditions and ensure optimal shielding effectiveness.

There are many types of foam molding methods. The most commonly used methods are the pressure foaming method, in which foam resin is mixed with a foaming agent at high temperature and high pressure, and the normal pressure foaming method, which foams at high temperature without pressure. The polymer resins used for foaming have different viscosities. For foaming under normal pressure, they need to be designed and analyzed for optimal foaming conditions, to obtain resins with low melt-viscosity or a narrow optimal viscosity range. This study investigated how changes in viscosity, molding temperature, and cross-link foaming conditions affected the characteristics of the molded foam, prepared by blending rubber polymer with biodegradable resin. The morphologies of cross sections and the cell structures of the normal pressure foam were investigated by SEM analysis. Properties were also studied according to cross-link/foaming conditions and torque. Also, the correlation between foaming characteristics was studied by analyzing tensile strength and elongation, which are mechanical properties of foaming composites.

We demonstrated an effective way of preparing melt spinnable mesophase pitches via catalytic hydrogenation of petroleum residue (fluidized catalytic cracking-decant oil) and their subsequent thermal soaking. The mesophase pitches thus obtained were analyzed in terms of their viscosity, elemental composition, solubility, molecular weight, softening point and optical texture. We found that zeolite-induced catalytic hydrogenation under high hydrogen pressure contributed to a large variation in the properties of the pitches. As the hydrogen pressure increased, the C/H ratio decreased, and the solubility in n-hexane increased. The mesophase pitch with entirely anisotropic domains of flow texture exhibited good meltspinnability. The mesophase carbon fibers obtained from the catalytically hydrogenated petroleum residue showed moderate mechanical properties.

Oxygen consumption is a useful parameter for evaluating mammalian embryo quality, since individual bovine embryos was noninvasively quantified by scanning electrochemical microscopy (SECM). Recently, several approaches have been used to measure the oxygen consumption rates of individual embryos, but relationship between oxygen consumption and pregnancy rates of Hanwoo following embryo transfer has not yet been reported. In this study, we measured to investigate the correlation between oxygen consumption rate and pregnancy rates of Hanwoo embryo using a SECM. In addition to, the expression of pluripotent gene and anti-oxidant enzyme was determined using real-time PCR by extracting RNA according to the oxygen consumption of in vivo embryo. First, we found that the oxygen consumption significantly increased in blastocyst-stage embryos (blastocyst) compared to early blastocyst stage embryos, indicating that oxygen consumption reflects the embryo quality (Grade I). Oxygen consumption of blastocyst was measured using a SECM and total cell number of in vitro blastocyst was enumerated by counting cells stained by propidium iodide. The oxygen consumption or GI blastocysts were significantly higher than those of GII blastocysts (10.2 × 1015/mols—1 versus 6.4 × 1015/mols—1, p<0.05). Total cell numbers of in vitro blastocysts were 74.8, 90.7 and 110.2 in the oxygen consumption of below 10.0, 10.0∼12.0 and over 12.0∼1015/mols—1, respectively. Pregnant rate in recipient cow was 0, 60 and 80% in the transplantation of embryo with the oxygen consumption of below 10.0, 10.0∼12.0 and over 12.0 × 1015/mols—1, respectively. GPX1 and SOD1 were significantly increased in over —10.0 group than below 10.0 groups but in catalase gene, there was no significant difference. On the other hand, In OCT-4 and Sox2, pluripotent gene, there was a significant difference (p<0.05) between the below-10.0 (0.98 ± 0.1) and over 10.0 (1.79 ± 0.2). In conclusion, these results suggest that measurement of oxygen consumption maybe help increase the pregnant rate of Hanwoo embryos.

Ski protein is a nuclear transcription factor that does not bind DNA directly. Due to its unique binding properties with multiple factors, Ski could perform various roles in the regulation of both cellular proliferation and differentiation. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to examine whether the initiation of luteinization with luteinizing hormone (LH) directly regulates expression of Ski in the luteinized granulosa and luteal cells after ovulation by in vitro models. RT-PCR and real time PCR analysis respectively revealed that LH had no effect on c-Ski mRNA expression in the cultured granulosa cells regardless of LH treatment. Though Ski protein isabsent in granulosa cells of preovulatory follicle, its mRNA(c-Ski) was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggested that its expression is regulated post-transcriptionally. Moreover, expression of mRNA of Arkadia, an E3 ubiquitin ligases, in luteinizing granulosa cells in vivo was assessed by real time-PCR. The levels of Arkadia mRNA expression were unchanged during follicular growth and post ovulatory luteinization. These findings suggest that Ski protein level may be regulated during luteinization at translational and/or post-translational level but not by Arkadia.

Sloan-Kettering virus gene product of a cellular pro-oncogene c-Ski is an unique nuclear pro-onco protein and belongs to the Ski/Sno proto-oncogene family. Ski plays multiple roles in a variety of cell types, it can induce both oncogenic transformation and terminal muscle differentiation when expressed at high levels. Ski protein is implicated in proliferation/differentiation in a variety of cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells, however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of this study was, by means of immunohistochemical methods, to locate Ski protein in the rat ovaries during ovulation and corpora lutea(CL) formation to predict the possible involvement of Ski in luteinization. In addition, to examine whether the initiation of luteinization with luteinizing hormone(LH) directly regulates expression of Ski in the luteinized granulosa and luteal cells after ovulation by in vivo models. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rat, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone(LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of corpus luteum(CL). These results indicate that Ski is profoundly expressed in the luteinized granulosa cells and luteal cells of CL during luteinization, and suggest that Ski may play a role in luteinization of granulosa cells.

For reconstituting genetic resource(Korean Native Chicken: KNC) with grem-line chimeric chicken made with cryopreserved biastdermal cells, the experiments were carried out to optimize cryopreservating conditions. Stage X biastdemal cells were collected from KNC embryos and dissociated. Cells were susupended in medium containing cyopretectant and fetal bovine serum(FBS), and distributed into plastic ampules. Cell susupensions were seeded to induce ice formation at — 7℃ to — 35℃ at in the experiments, the effect of modification of dissociation way, concentration of FBS and cell density on the vaibility of frezen-thawed cells were investigated by trypan blue exclusion. Then change the way of cell dissociation from pipetting to short time vortexing, viability of frozen- thawed cell tended to be increaced from 29 % to 52 %. Increase concentraition of FBS in frozen medium from 20 % to 80 % made viability of thawed cell from 28 % to 35 %. The viability of thawed cells were 33.9% frozen at 2 embryos/ 0.5 ml, and 43.6 % frozen at 20embryos/0.5 ml. Furthermore, combination of three modifications make big improvement. The viability of frozen-thawed cell was 60 % for combinated method, and 41 % for general method. This result means the advance to practical cryoreservation of blastdermal cell of the KNC(Ogolgye breed).

Ski protein is implicated in proliferation/differentiation in a variety of cells. We had previously reported that Ski protein is present in granulosa cells of atretic follicles, but not in preovulatory follicles, suggesting that Ski has a role in apoptosis of granulosa cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells; however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of the present study was to locate Ski protein in the rat ovary during luteinizationto predict the possible role of Ski. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rats, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of the corpus luteum (CL). Though Ski protein is absent in granulosa cells of preovulatory follicle, its mRNA (c-Ski)was expressed and the level was unchanged even after LH surge. Taken together, these results demonstrated that Ski protein expression is induced in granulosa cells upon luteinization, and suggests that its expression is regulated post-transcriptionally.

For reconstituting genetic resource(Korean Native Chicken: KNC) with grem-line chimeric chicken made with cryopreserved biastdermal cells, the experiments were carried out to optimize cryopreservating conditions. Stage X biastdemal cells were collected from KNC embryos and dissociated. Cells were susupended in medium containing cyopretectant and fetal bovine serum(FBS), and distributed into plastic ampules. Cell susupensions were seeded to induce ice formation at —7 ℃ to —35 ℃ at in the experiments, the effect of modification of dissociation way, concentration of FBS and cell density on the vaibility of frezen-thawed cells were investigated by trypan blue exclusion. Then change the way of cell dissociation from pipetting to short time vortexing, viability of frozen-thawed cell tended to be increaced from 29 % to 52 %. Increase concentraition of FBS in frozen medium from 20 % to 80 % made viability of thawed cell from 28 % to 35 %. The viability of thawed cells were 33.9% frozen at 2 embryos/ 0.5ml, and 43.6 % frozen at 20 embryos/0.5 ml. Furthermore, combination of three modifications make big improvement. The viability of frozen-thawed cell was 60 % for combinated method, and 41 % for general method. This result means the advance to practical cryoreservation of blastdermal cell of the KNC(Ogolgye breed).

Advanced multidetector CT (MDCT) technology provides 2-dimensional (2D) images with 3-dimensional (3D) images. These 3D images (volume rendered, VR images) demonstrates the surface of the body and cutaneous neurofibromas in pa-tients with neurofibromatosis (NF) are well visualized. MDCT is a very useful imaging modality that represents various findings of neurofibromatosis such as cutaneous neurofibromas, central nervous tumors, skeletal anomalies including verte-bral scalloping and dural ectasia, mediastinal masses, lung parenchymal diseases, vascular anomalies, and complicated dis-eases related with NF. Herein, we report three cases with NF presenting cutaneous neurofibromas diagnosed by MDCT; One is NF patient with dural ectasis and meningocele, second case is a patient with NF and horseshoe kidney, third case is a pa-tient with cutaneous and subcutaneous neurofibromas.

The goals of this study were to investigate image quality of coronary CT angiography (CCTA) and change of radiation dose by using Adaptive Statistical Iterative Reconstruction (ASIR) technique. 40 subjects with BMI≥25 (A, C groups), 40 subjects with BMI<25 (B, D groups), Groups without ASIR (A, B groups), and with ASIR (C, D groups) were included. There were no statistical differences in image qualities (p>0.05). Radiation doses with application of ASIR were significantly lower than those of ASIR (51-53%, p<0.05). In CCTA scan-nings, ASIR technique helps to reduce radiation dose with preserved image quality.

This study was undertaken to evaluate the association between the appearance of hypodense hepatic nodules on dynamic CT images and acute alcoholic hepatitis in patients with alcoholic cirrhosis. Sixty-two patients (male:female=57:5, mean age=51.4±10.9 years) with alcoholic cirrhosis were included. Patients were divided into 3 groups; group A (nodules, n=23), group B (fatty liver < 40 Hounsfield unit (HU) without nodules, n=18), and group C (control, n=21). Liver nodules in Group A had characteristic low density during pre- and all post-contrast phases versus liver parenchyma and fewer or complete resolution of nodules on follow up CT after alcohol withdrawal. Densities (HU) of nodules and hepatic parenchyma, ascites scores, and laboratory values were analyzed. Mean densities of hepatic parenchyma in groups A and B were significantly lower than in the control group. Serum bilirubin, AST (aspartate transaminase), ALT (alanine transaminase), PT (prothrombin time), and ascites scores were significantly higher in group A than in the other two groups. As numbers of liver nodules increased nodules’ attenuation decreased. Mean serum AST and ALT were higher in patients with many nodules than in patients with few nodules. Hypodense hepatic nodules in alcoholic steatohepatitis in patients with alcoholic cirrhosis are probably benign nodules resulting from focal steatosis or hepatocellular necrosis rather than metastases.

Spontaneous rupture of the carotid artery is rare, however, it is a fatal injury and early diagnosis is very important. We expe-rienced a 54-year-old male patient who presented to the emergency department with an expanding neck mass after cough. Rupture of the common carotid artery 2 cm before bifurcation with a pseudoaneurysm was diagnosed on neck computed tomography angiography. Focal tear of the artery was repaired surgically with suture. Herein, we report on a rare occurrence of a spontaneous carotid artery rupture and review other reports.

The purpose of this study is to evaluate the changes of liver and gallbladder in patients with acute hepatitis A during transabdominal ultrasonography (US). In this study, we included 61 patients with acute hepatitis A and 50 controls. Wall thickness and lumen diameter of gallbladder were measured for determined the mural edema and hypertonicity of gallbladder. To evaluate the hepatic size and stiffness, two sagittal images of the left lobe of the liver were obtained during the resting state (resting image) and at full inspiration (stress image). The elongation rate was calculated by a formula: (L2-L1/L1)×100 (%); where L1 and L2 are the length of the liver for both the resting and stress image. The elongation rate was compared between controls and patients with acute hepatitis A. The wall thickness and lumen diameter of gallbladder were 7.0±3.5mm, 10.2±9.9mm, respectively. In 21 cases (34%), the lumen of gallbladder was collapsed. The mean diameter of left lobe in patients with acute hepatitis A (10.3±1.4cm)was larger than that of controls (8.2±1.1cm). The elongation rate in patients with acute hepatitis A (8.0±8.8%) was smaller than that of controls (25.5±13.4%). Robust US findings in patients with acute hepatitis A were edematous gallbladder with collapse and hepatomegaly with stiffness.

We report on a rare case of a 26-year-old man with neurofibromatosis type I who presented with cramping abdominal pain caused by stones within a horseshoe kidney. He also showed extensive neurofibromas in his neck, thorax, and abdominopel-vic cavity. He had undergone excision of a subcutaneous neurofibroma from his left flank a few years prior. Treatment by extracorporeal shock wave lithotripsy (ESWL) was administered twice. Stones were removed completely and his symptoms were resolved.

In this study, we identified 26 cases scheduled for lower extremity computed tomography (CT) angiography who had implanted metal devices. These CT exams were performed for evaluation of patients' symptoms related with gait disturbance. CT scans were performed on 128-MDCT using our standard parameters. The row image data were reconstructed using two different methods, standard filtered backprojection (FBP) algorithm and the metal artifact reduction for orthopedic implants (O-MAR) algorithm. Images were evaluated with 3-point scales. The difference of image scores for FBP (1.5±0.81) and OMAR (1.92±0.79) was significant (p<0.05). O-MAR reconstruction significantly improved quality of CT angiography for patients with metal implants.

The purpose of this study is to evaluate perfusion density of an old myocardial infarction using cardiac multidetector computed tomography (MDCT) with arterial phase. We included 56 patients with an old myocardial infarction who had undergone medical treatment, primary angioplasty or bypass graft. Cardiac MDCT without stress perfusion was used for calculation of density of myocardial perfusion and global left ventricular function in patients was also analyzed according to initial and last follow-up echocardiography. All patients showed decreased perfusion in the left ventricular wall. Densities of normal ventricular wall, cavity of the left ventricle, and infracted wall were 105±29 HU, 471±117 HU, and 11±29 HU (-64 HU-57 HU), respectively. Subendocardial fat depositions were observed in 19 patients (34%). Ejection fractions of initial and last follow-up periods near to the date of cardiac CT were 61±9 % and 57±12 %, respectively. In conclusion, decreased perfusion less than 60 HU in cardiac CT with arterial phase was helpful in diagnosus of an old myocardial infarction.

This experiment was conducted to investigate the variation of nitrogen use efficiency, nitrogen uptake efficiency, physiological utilization efficiency and their relationships with growth characteristics in the 28 Korean rice cultivars. Nitrogen use efficiency of 28 rice cultivars was 47.74, nitrogen uptake efficiency was 0.71, and physiological utilization efficiency was 68.76 in average. Nitrogen use efficiency of rice cultivars had low variation ranged from 44.09 to 51.91, but nitrogen uptake efficiency were relatively high variation from 0.51 to 0.90, and physiological utilization efficiency was from 51.71 to 94.26. The high efficient group in nitrogen uptake efficiency whose value was calculated above 0.80 included Daeanbyeo, Seojinbyeo, Ansungbyeo, Dongjinbyeo, and Hwaanbyeo, while the low efficient group with below 0.60 was Kwanganbyeo, Sampyeongbyeo, Soorabyeo, and Hwasungbyeo. Hwasungbyeo, Sampyeongbyeo, Soorabyeo for physiological utilization efficiency were more efficient cultivars, while Daeanbyeo, Seojinbyeo, Ansungbyeo were less efficient cultivars. Nitrogen uptake efficiency had positive correlation coefficients between dry matter weight of plant (0.842** ), leaf area index (0.761** ), and leaf nitrogen content (0.599** ), respectively. Therefore, the dry matter weight of rice plant and leaf area index was important characters to evaluate nitrogen uptake efficiency in rice cultivars. Also, more efficient cultivar in nitrogen uptake had higher chlorophyll meter value, which was appeared dark green color.