• Journal of the Korean Electrochemical Society
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• v.18 no.3
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• pp.121-129
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• 2015

The platinum anode for the electrolytic reduction process is generally surrounded by a nonporous ceramic shroud with an open bottom to offer a path for $O_2$ gas produced on the anode surface and prevent the corrosion of the electrolytic reducer. However, the $O^{2-}$ ions generated from the cathode are transported only in a limited fashion through the open bottom of the anode shroud because the nonporous shroud hinders the transport of the $O^{2-}$ ions to the anode surface, which leads to a decrease in the current density and an increase in the operation time of the process. In the present study, we demonstrate the electrolytic reduction of 1 kg-uranium oxide ($UO_2$) using the porous shroud to investigate its long-term stability. The $UO_2$ with the size of 1~4mm and the density of $10.30{\sim}10.41g/cm^3$ was used for the cathode. The platinum and 5-layer STS mesh were used for the anode and its shroud, respectively. After the termination of the electrolytic reduction run in 1.5 wt.% $Li_2O-LiCl$ molten salt, it was revealed that the U metal was successfully converted from the $UO_2$ and the anode and its shroud were used without any significant damage.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1236-1247
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• 2014

Gamma irradiated-treatment of natural medicinal plants can be used to improve extraction transference number and for qualitative improvement of color when applied to functional material exploration. This study investigated the biological activities of Aralia elata cortex extracts upon gamma irradiation. In addition, different physical techniques [photostimulated luminescence (PSL) and thermoluminescence (TL)] were used for irradiation identification of Aralia elata cortex. In PSL analysis, non-irradiated (0 kGy) sample showed a negative result of 400 photon counts (PCs), whereas irradiated (5, 10, and 30 kGy) samples showed positive results of 90,100.00, 312,614.33, and 321,661.67 PCs, respectively. In the TL method, growth curve showed very unusual behaviors around $200^{\circ}C$ upon natural-irradiation of the non-irradiated (0 kGy) sample and around $150{\sim}250^{\circ}C$ for the irradiated (5, 10, and 30 kGy) samples. The TL ratio was 0.1 in non-irradiated samples at 0.011, whereas the values of irradiated samples (5, 10, and 30 kGy) were 0.1 at 1.105, 1.009, and 2.206, respectively. For phenolics of gamma-irradiated Aralia elata cortex, water and 50% ethanol extracts had the highest amounts, $17.30{\pm}0.40mg/g$ and $18.87{\pm}0.46mg/g$ at 10 kGy irradiation, respectively. The inhibitory activities of angiotensin-converting enzyme and xanthin oxidase were higher in both irradiated water and 50% ethanol extracts than in non-irradiated ones. For pancreatin ${\alpha}$-amylase and ${\alpha}$-glucosidase inhibitory activities, water and 50% ethanol extracts containing $200{\mu}g/mL$ of phenolics showed high inhibitory activities of 60~100% at all irradiation doses (0~30 kGy). This result confirmed that Aralia elata cortex extracts have greater anti-diabetic effects than acabose as a diabetic remedy. Gamma-irradiated Aralia elata cortex extracts are useful as a functional material with anti-diabetic effects. Thus, Aralia elata cortex extracts can be used as a functional material with various biological activities, and gamma-irradiation can be used to amplify biological activities in plants.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1217-1227
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• 2014

This study investigated the physicochemical properties and antioxidant activity of vinegar added with different levels (0%, 1%, 3%, 5%, and 7%) of Akebia quinata fruit during two-step fermentation. The physicochemical properties of vinegar evaluated were pH, total acidity, alcohol, and total sugar and amino acid contents. The antioxidant activities were based on ABTS radical scavenging activity, SOD-like activity, and reducing power. During alcohol fermentation, total acidity and alcohol contents of vinegar increased, but total sugar contents decreased. During acid fermentation, total acidities of vinegar increased. Vinegar added with 7% A. quinata fruit showed the highest total sensory score. Total polyphenol contents of vinegar added with 0% and 1% A. quinata fruit were not significantly different. However, vinegar added with 3, 5, and 7% A. quinata fruit showed significantly higher total polyphenol contents of 136.6, 381.59, and 415.35 mg/100 g, respectively, after 13 days of fermentation. Further, total flavonoid contents of vinegar added with 0~7% A. quinata fruit significantly increased to 21.73, 15.79, 15.15, 26.19, and 26.87 mg/100 g, respectively, after 13 days of fermentation. In addition, tannin contents of vinegar added with 0~7% A. quinata fruit significantly increased to 0.2042, 0.2004, 0.1255, 0.1384, and 0.1255 mg/100 g, respectively, after 13 days of fermentation. Moreover, ABTS radical scavenging activities of vinegar added with 0~7% A. quinata fruit significantly increased to 5.87, 12.59, 25.63, 34.02, and 35.25, respectively, after 13 days of fermentation at a concentration of 5 mg/mL. Additionally, SOD-like activities of vinegar added with 0~7% A. quinata fruit significantly increased to 8.22, 17.49, 16.86, 16.89, and 15.68%, respectively, after 13 days of fermentation. Reducing power of 7% A. quinata fruit was 0.527 after 1 day and 1.539 at the end of fermentation. Our results demonstrate that antioxidant activity significantly increased during fermentation according to the content of A. quinata. Further, the total polyphenol, flavonoid, and tannin contents were shown to be closely related with antioxidant activities. Thus, A. quinata could be effectively used as a vinegar and functional food material based on its antioxidant activity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.4
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• pp.490-500
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• 2017

This study was performed to evaluate repeated dose oral toxicity upon administration of the test substance 1,2-benzisothiazolin-3-one for 90 days and to determine NOAEL (no observed adverse effect level) and target organs in Sprague-Dawley rats. Single, 2-week repeated, and 13-week repeated oral dose toxicity studies were conducted in Sprague-Dawley rats. The dose levels of groups were 1,250, 2,500, and 5,000 mg/kg/d. All dose groups were compared with the vehicle control group. The animals were observed for clinical signs and weekly body weight. Urinalysis, hematology, and serum biochemistry analyses were conducted. Subsequently, animals were sacrificed and subjected to histopathological examination. For the result, NOAEL of ethanol extract from unripe fruit of bitter melon had an optimal dose of 5,000 mg/kg/d and acceptable daily intake up to 3,000 mg/man. There was no target organ detected. Therefore, bitter melon, which contains a variety of bioactive substances, could be widely used as a health functional food ingredient.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.5
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• pp.562-571
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• 2017

In this study, we investigated the anti-oxidant activities [electron-donating ability (EDA), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging ability, and reactive oxygen species (ROS) inhibitory activity], anti-wrinkle activities [collagenase inhibitory activity, suppression and/or phosphorylation of matrix metalloproteinases (MMPs), and mitogen-activated protein (MAP) kinase activity], and mRNA expression levels using reverse transcription-polymerase chain reaction (RT-PCR) assay in ultraviolet (UV) B ray ($50mJ/cm^2$)-irradiated human keratinocyte HaCaT cells. Josaengheugchal, Sinneungheugchal (SE), Shintoheug rice, Heugjinju rice, and Heugseol (HE) among colored rice varieties were reported to have excellent antioxidant properties. In the EDA and ABTS radical scavenging assays, extracts of the five colored rice varieties had scavenging activities of 72% at concentrations higher $50{\mu}g/mL$. In the collagenase inhibition assay, ethanol extracts of the five colored rice varieties showed high inhibitory effects of about 60% at concentrations higher $25{\mu}g/mL$. In the ROS inhibition assay, ethanol extracts of HE and SE showed very excellent inhibition efficacies at all concentrations. We determined molecular biological mechanisms of MMPs (MMP-1, -3, -8, and -13) and mitogen-activated protein kinase (MAPK) with HE, and the results show that HE suppressed expression of MMPs and phosphorylation of MAPK and increased expression of pro-collagen type I in UVB-irradiated cells. It was also confirmed by RT-PCR that HE reduced expression of MMPs mRNA. Therefore, these results suggest that HE has anti-wrinkle and collagen production effects and may be used as a material in the development of functional food and cosmetic industries.

• Journal of the korean academy of Pediatric Dentistry
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• v.33 no.2
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• pp.290-303
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• 2006

Tooth eruption is a complex and tightly regulated process that involves cells of the tooth organ and the surrounding alveolus. Osteoclast precursors must be recruited into the dental follicle prior to the onset of eruption. This function of dental follicle may be regarded as the ability of bone remodeling characterized by the interaction of osteoclasts and osteoblasts. This is because tooth eruption is a localized event in which many of the genes required for eruption are expressed in the dental follicle. RANKL is a membrane-bound protein that is a member of the TNF ligand family. which is present on bone marrow stromal cells and osteoblasts, and induces osteoclast formation and activation from precursor cell. The biologic effect of RANKL is inhibited by OPG and, in bone, the relative ratio of RANKL and OPG modulates osteoclastogenesis. To evaluate the roles of RANKL and OPG in tooth eruption and the relations with the expression pattern of Runx2, in situ hybridization was performed with mandibles of mice at postnatal stage 1, 3, 5, 7, 9 and 11. mRNA of RANKL, OPG, and Runx2 are expressed in dental follicle and surrounding tissue from P1 to 11. To determine the sites of osteoclastic activity during tooth eruption, mandibles were dissected. Peak osteoclastic activity in alveolar bone along the occlusal and basal regions was observed from P5 to 9, with osteoclasts in these regions being large and strongly TRAP-positive The specific spatio-temporal expression patterns of RANKL, OPG, and Runx2 in our study suggest that tooth eruption could be progressed through the interactions of molecular signaling among dental follicle, dental organ and alveolar bone, furthermore it means that dental follicle is quite important in tooth eruption In addition, it indicates that these genes (RANKL, OPG, and Runx2) play critical roles in tooth eruption.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.219-227
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• 2001

Little is known about processing mechanism of pain sensation of the oral cavity at the 1st synapse of trigeminal sensory nuclei. Serial ultrathin sections of tooth pulp afferent terminals, identified by the transganglionic transport of 1% wheatgerm agglutinin conjugated horseradish peroxidase, were investigated with electron microscope. Quantitative ultrastructural analysis was performed on digitizing tablet connected to Macintoshi personal computer (software; NIH Image 1.60, NIH, Bethesda, MD). Labeled boutons could be classified into two types by the shapes of containing vesicles : S bouton, which contained mainly spherical vesicles (Dia. 45-55 nm) and few large dense cored vesicles (Dia, 80-120nm), and LDCV bouton, which contained spherical vesicles as well as large number of large dense cored vesicles. Most of the parameters on the ultrastructural characteristic and synaptic organization of labeled boutons were similar between S and LDCV boutons, except shapes of containing vesicles. Majority of the labeled boutons showed simple synaptic arrangement. The labeled boutons were frequency presynaptic to dendritic spine, and to a lesser extent, dendritic shaft. They rarely synapsed with soma and adjacent proximal dendrite. A small proportion of labeled boutons made synaptic contacts with presynaptic, pleomorphic vesicles containing endings and synaptic triad. Morphometric parameters of labeled boutons including volume and surface area, total apposed area, mitochondrial volume, active zone area, vesicle number and density showed wide variation and these were not significantly different between S and LDCV boutons. The present study revealed characteristic features on ultrastructure and synaptic connection of pulpal afferents which may involved in transmission of oral pain sensation.

• Journal of The Korean Association For Science Education
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• v.12 no.1
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• pp.75-92
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• 1992

The purpose of this study was to point out the problems of the competency exam for college education, a new college entrance exam, and to suggest the improvement ideas for it For this purpose, the test items of science inquiry were taken from the first, the second and the third pilot studies of the competency exam for college education which National Institute of Educational Evaluation had done. These tests were administered to 1,223 students of the general high school(422 for the 1st 400 for the 2nd, and 401 for the 3rd test). Also, those students' and the high school science teacher's opinions about the tests and the new college entrance exam were surveyed. The evaluation objectives of those test items were analyzed and the test item analyses were done. The results were as follows; (1) The evaluation objective analysis showed that most of the test The purpose of this study was to point out the problems of the competency exam for college education, a new college entrance exam, and to suggest the improvement ideas for it For this purpose, the test items of science inquiry were taken from the first, the second and the third pilot studies of the competency exam for college education which National Institute of Educational Evaluation had done. These tests were administered to 1,223 students of the general high school(422 for the 1st, 400 for the 2nd, and 401 for the 3rd test). Also, those students' and the high school science teacher's opinions about the tests and the new college entrance exam were surveyed. The evaluation objectives of those test items were analyzed and the test item analyses were done. The results were as follows; (1) The evaluation objective analysis showed that most of the test items were constructed based on the evaluation framework which was composed of scientific inquiry thinking ability, science concept, and scientific inquiry context dimensions. But, those items were unevenly distributed into a few areas of the evaluation framework. (2) The boys had higher mean scores than the girls in all of the tests, but these differences were not statistically significant. The natural science course students had significantly higher mean than the humanities course students in all of the test:(1st, F=12.643, p=0.0004 ; 2nd, F=45.757, p=0.0001 ; 3rd, F=36.162, p=0.0001). A significant interaction of sex and course was found in only 1st test( F=11.352. p=0.0008). (3) Most students answered the test was difficult and they needed more time to finish it Also, they added they had to study in a different way from the traditional one in order to prepare the new college entrance exam. Science teachers answered that those evaluation objectives of the tests corresponded well with the educational objectives of high school science and that the tests were suitable as measuring instruments of the scientific thinking abilities. But they pointed out it would be very difficult for them to teach students for preparing the exam under the exsting educational conditions. To carry out successfully the competency exam for college education, the following improvements were suggested. (1) Good evaluation methodology should be developed. (2) In-service science teacher training models on evaluation should be put in force. (3) Effective teaching models and strategies should be developed.(4) The high school science curriculum should be revised.

• Tuberculosis and Respiratory Diseases
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• v.41 no.3
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• pp.262-269
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• 1994

Background : A clinical study was carried out on 153 new cases with small cell lung cancer registered at Presbyterian Medical Center, Chonju during the 7 years from 1986 to 1992. They were analyzed by sex and age distribution, symptoms and signs, classification of stage and site and its treatments. Especially, an effort was made to compare the overall survival time between limited stage and extensive stage. Methods : Among 806 lung cancer patients diagnosed by biopsy or cytologic evaluation for the 7 years, 153 patients was shown small cell lung cancer. These 153 cases was analyzed retrospectivery through patient's records, letters or telephones. Results : The results of evaluation of small cell lung cancer are as follows. Over 85 percent of the small cell lung cancer patients were over 50 years of age and prominent clinical features were cough(86.3%), sputum(75.8%) and dyspnea(54.9%). One hundred and five patients(68.7%) was staged to have limited stage. Mean survival time of the chemotherapy and chemoradiotherapy in limited stage has significant difference and its survivals are 5.3 months and 15.0 months. Patients whose disease was staged as limited, regardless of whether or not chemotherapy was administered, had a median survival time of 10.9 months, compared with 4.8 months for those with extensive stage. Conclusion : Lung cancer is one of the malignant diseases tend to increase gradually in Korea and proven to be the most common cancer next to the gastric cancer among various cancers in males found at the Presbyterian Medical Center in the past seven years. This report is a retrospective view of the clinical therapeutic results of the small cell lung cancer patients. Especially at the limited stage, the combined therapy revealed higher survival rate than the chemotherapy alone. For a more accurate evaluation. a prospective view, without any bias, of patients selected at random is needed.

• Tuberculosis and Respiratory Diseases
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• v.44 no.2
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• pp.401-408
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• 1997

Background : Pulmonary sequestration is a rare congenital malformation, which is manifested by formation of nonfunctioning lung tissue lacking normal communication with the tracheobronchial tree. The preoperative diagnostic rate has been relatively low, and without consideration of pulmonary sequestration, unexpected bleeding from aberrant vessels may be a serious problem during the operation. The purpose of our study is to describe the clinical features of pulmonary sequestration based on a review of 15 cases treated by operation. Method : Fifteen patients with pulmonary sequestration who had undergone surgical treatment from 1991 through May 1996 at Yongdong Severance Hospital and Severance Hospital were reviewed retrospectively. Results : The mean age of the patients was 22.5 years (range 5~57), and male to female ratio was 9 : 6. Clinical presentations varied from recurrent respiratory infections such as fever, cough, and sputum or chest pain to no symptom. The chest simple X-rays showed multicystic shadow(10/15) and solid mass-like shadow(5/15). The chest CT scans, done in twelve cases, showed multicystic lesion with or without lung infiltration(8/12), solid mass-like lesion(4/12), The chest MRIs, done in three cases, revealed the aberrant arteries originating from descending aorta(2/3). Aortograms, done in four cases, showed the aberrant arteries originating from descending thoracic aorta(2/4), abdominal aorta(I/4), and intercostal artery(1/4). and the venous returns were via the pulmonary veins. Pulmonary sequestration was considered preoperatively in six patients of fifteen. Other preliminary diagnosis were lung tumor(3/15), lung abscess(21/15), bronchiectasis(2/15), and mediastinal tumor(2/15). In the operative findings, twelve cases were of intralobar type and three cases of extralobar type. The left lower lobe was most often affected(9/15) and one extralobar sequestration was in the pericardium. The aberrant arteries originated from descending thoracic aorta(6/15), abdominal aorta(1/15), internal thoracic arteries (2/15), intercostal artery(1/15), pericardiophrenic artery(1/15), but in four cases, the origins could not be defined. There was no mortality or complication postoperatively. Conclusion : In our study, preoperative diagnostic rate was relatively low, and clinical features were similar to previous reports. Preoperative vigorous diagnostic approach including aortography is strongly advocated not only for its diagnostic value, but also for accurate localization of the aberrant vessels, which is major concern to surgical procedure.