• Journal of Radiation Protection and Research
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• v.48 no.1
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• pp.15-19
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• 2023

Background: Cone beam computed tomography (CBCT) is a specialized medical equipment and plays a significant role in the diagnosis of oral and maxillofacial diseases and abnormalities; however, it is attributed to risk of exposure of ionizing radiation. The aim of the study was to estimate and determine the amount of scattered radiation dose to the thyroid gland in dental CBCT during maxilla and mandible scan. Materials and Methods: The average scattered radiation dose for i-CAT 17-19 Platinum CBCT (Imaging Sciences International) was measured using a Multi-O-Meter (Unfors Instruments), placed at the patient's neck on the skin surface of the thyroid cartilage, with an exposure parameter of 120 kVp and 37.07 mAs. The surface entrance dose was noted using the Multi-O-Meter, which was placed at the time of the scan at the level of the thyroid gland on the anterior surface of the neck. Results and Discussion: The surface entrance dose to the thyroid from both jaws scans was 191.491±78.486 µGy for 0.25 mm voxel and 26.9 seconds, and 153.670±74.041 µGy from the mandible scan, whereas from the maxilla scan the surface entrance dose was 5.259±10.691 µGy. Conclusion: The surface entrance doses to the thyroid gland from imaging of both the jaws, and also from imaging of the maxilla and mandible alone were within the threshold limit. The surface entrance dose and effective dose in CBCT were dependent on the exposure parameters (kVp and mAs), scan length, and field of view. To further reduce the radiation dose, care should be taken in selecting an appropriate protocol as well as the provision of providing shielding to the thyroid gland.

• Journal of Microbiology and Biotechnology
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• v.11 no.4
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• pp.649-655
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• 2001

The kinetics of the thermolysin-catalyzed synthesis of N-(benzyloxycarbonyl)-L-phenylalanyl-L-leucine ethyl ester (Z-Phe-LeuOEt) from N-(benzyloxycarbonyl)-L-phyenylalanine (Z-Phe) and L-leucine ethyl ester (LeuOEt) in an ethyl acetate saturated aqueous system in a batch operation were studied. The kinetics for the synthesis of Z-Phe-LeuOEt were expressed using a rate equation for the rapid equilibrium random bireactant mechanism. The four kinetic constants involved in the rate equation were determined numerically by the quasi-Newton method so as to fit the calculated results with the experimental data. Within the pH and temperature range examined, the $K_{cat}$ value for the synthesis of Z-Phe-LeuOEt reached a maximum at pH 7.0 and $45^{\circ}C$, whereas the affinity between Z-Phe and thermolysin reached a maximum at pH 6.0 adn $40^{\circ}C$. The inhibitory effect of Z-Phe on the condensation reaction decreased as the pH and temperature decreased. In contrast, they affinity between LeuOEt and thermolysin remained unchanged within the pH and temperature range examined. Therefore, it was concluded that the protonation state of the carboxyl groups. of Z-Phe was more imprtant than that of the amono groups of LeuOEt for the synthesis of Z-Phe-LeuOEt in the present solvent system. The equilibrium yield at pH 6.0 and $30^{\circ}C$ was 8% higher than that at pH 7.0 and $40^{\circ}C$, although the rate was much slower. This result suggested that the affinity between the enzyme and the substrate rather than the overall rate was a more important factor affecting the equilibrium yield, when the peptide synthesis was carried out in a product-precipitation system.

• Korean Journal of Human Ecology
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• v.24 no.3
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• pp.423-436
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• 2015

Namdaemun Market is located in the heart of history and has the volume and the budget for nearly half of the total Namdaemun. But it has been undergoing the crisis of stagnation without reviving the merit of only the 'jewelry' wholesale industrial cluster in the nation. The purposes of this study were that analyzed the status and design of jewelry in Namdaemun and identified the characteristics of successful domestic jewelery brands and then the revitalized the way of the Namdaemun jewelry industry. Problems being currently facing the Namdaemun jewelry shopping are most likely caused by products' design did not respond to changes quickly, while China's jewelry products are in leaps of the quality and the affordable jewelry market in Korea has lost the large number of the customers by china's cheap jewelry products. The most feature of successful domestic jewelry companies, Red Eye, Naughty Cat and Jackie Moon. put the most effort to unique design development and then constantly develope new designs to meet the diverse needs of consumers. It is a conclusion that the Namdaemun jewelry market need to produced under the name of brand not by the traditional whole sale market style. Development unique jewelry brand requires a high-end commercial strategy of the logo, packaging and interior. The high-end quality require for the advanced designs as well as the study of new materials needed for the advanced materials.

• Restorative Dentistry and Endodontics
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• v.29 no.3
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• pp.239-248
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• 2004

The purpose of this study was to investigate the influence of NK1 receptor antagonists on the pulpal blood flow (PBF) when applied iontophoretically through the dentinal cavity of the teeth in order to understand whether iontophoretically applied NK1 receptor antagonists can control the pulpal inflammation. Eleven cats were anesthetized with alpha-chloralose and urethane, and substance P (SP) was administered to the dental pulp through the catheterized lingual artery in doses that caused PBF change without the influence of systemic blood pressure. NK1 receptor antagonists were applied iontophoretically to the prepared dentinal cavity of ipsilateral canine teeth of the drug administration, and PBF was monitored. Data were analyzed statistically with paired t-test. PBF increase after iontophoretic application of the NK1 receptor antagonists followed by the intra-arterial administration of SP was significantly less than PBF increase after iontophoretic application of the 0.9% saline followed by the intra-arterial administration of SP as a control (p < 0.05). Iontophoretic application of the NK1 receptor antagonists (0.2~3.4 mM) following the intra-arterial administration of SP resulted in less increase of PBF than the iontophoretic application of the 0.9% saline following the intra-arterial administration of SP as a control (p < 0.05). Therefore. the results of the present study provide evidences that the iontophoretic application is an effective method to deliver drugs to the dental pulp. and that iontophoretically applied NK1 receptor antagonists block SP-induced vasodilation effectively. The above results show the possibility that the iontophoretical application of NK1 receptor antagonists can control the neurogenic inflammation in the dental pulp.

• YAKHAK HOEJI
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• v.51 no.4
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• pp.285-290
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• 2007

The oxidative stress causes many diseases like cancer, aging, cardiovascular disease, degenerative neurological disorders (Parkinson’s disease, and Alzheimer's disease) by damage of cell membrane, protein deformation, and damage of DNA due to the oxidation of lipid of cell membrane, protein of tissue or enzyme, carbohydrate, and DNA. It is caused by the reactive oxygen species (ROS) that is produced in the metabolic process of oxygen in cell. The superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) in cell systemize the antioxidative enzymes to control the oxidative stress. In this research, it is measured that the survival rate of cell by the typical isoflavonoid of daidzein or genistein, activity of antioxidative enzyme, and ROS level, in order to study the effect of isoflavonoid over the ROS production in cell and antioxidative system. As the similar action of the isoflavonoid with the estrogen is examined, women are encouraged to get bean. In view of this trend, it is very important to find out a combination medicine that lowers the oxidative stress caused by the daidzein in the ovarian cell. In the combined treatment of the typical antioxidant of vitamin C to oxidative stress which induced by daidzein recover the control level particularly lowering the ROS in cell by 30%. However, it made no effect in the combined treatment with genistein. Therefore, the research took the combination effect of daidzein with vitamin C in order to check it effect over the antioxidative system. In conclusion, it was disclosed that the oxidative stress caused by daidzein is related to the lowering activity of SOD, and the specific combination effect of daidzein with vitamin C is related to the recovery of SOD activity.

• Journal of Microbiology and Biotechnology
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• v.23 no.1
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• pp.7-14
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• 2013

In the Bacillus amyloliquefaciens ${\alpha}$-amylase (BAA), the loop (residues 176-185; region I) that is the part of the calcium-binding site (CaI, II) has two more amino acid residues than the ${\alpha}$-amylase from Bacillus licheniformis (BLA). Arg176 in this region makes an ionic interaction with Glu126 from region II (residues 118-130), but this interaction is lost in BLA owing to substitution of R176Q and E126V. The goal of the present work was to quantitatively estimate the effect of ionic interaction on the overall stability of the enzyme. To clarify the functional and structural significance of the corresponding salt bridge, Glu126 was deleted (${\Delta}$E126) and converted to Val (E126V), Asp (E126D), and Lys (E126K) by site-directed mutagenesis. Kinetic constants, thermodynamic parameters, and structural changes were examined for the wild-type and mutated forms using UV-visible, atomic absoption, and fluorescence emission spectroscopy. Wild-type exhibited higher $k_{cat}$ and $K_m$ but lower catalytic efficiency than the mutant enzymes. A decreased thermostability and an increased flexibility were also found in all of the mutant enzymes when compared with the wild-type. Additionally, the calcium content of the wild-type was more than ${\Delta}E126$. Thus, it may be suggested that ionic interaction could decrease the mobility of the discussed region, prevent the diffusion of cations, and improve the thermostability of the whole enzyme. Based on these observations, the contribution of loop destabilization may be compensated by the formation of a salt bridge that has been used as an evolutionary mechanism or structural adaptation by the mesophilic enzyme.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.27 no.2
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• pp.109-118
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• 2016

Objectives: The aim of this study was to develop the computerized Comprehensive Learning Test-Reading (CLT-R) to evaluate the cognitive processes and achievements related to their basic reading ability and identify dyslexia in children and adolescents in South Korea. We also obtained the normative data and evaluated the reliability and validity of the test. Methods: We developed the CLT-R, including the word attack/nonword decoding, paragraph reading, sound blending, nonword repetition, rapid automatized naming, letter-sound matching, visual attention, orthography awareness, and digit span tests, for the purpose of diagnosing dyslexia. We investigated the reliability and validity of the tests and gathered the normative data from 399 subjects (male 48.9%), aged 5-14 years, from the last grade in kindergarten to middle school, dwelling in Seoul and Gyeonggi Province, South Korea. Results: No statistical differences were observed between the means of the tests and retests of the CAT. The mean of the correlation coefficient of the test-retest scores was 0.85. According to the construct validity test calculated by principal constant analysis using the oblique rotation method, 4 factors explained 70.0% of the cumulative variances. In addition, the normative data were obtained for all of the CLT-R subtests. Conclusion: The computerized CLT-R can be used as a reliable and valid tool to evaluate the reading achievement and reading related cognitive process in Korean children and adolescents in schools, clinics, and research institutes.

• Nutritional Sciences
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• v.9 no.4
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• pp.248-258
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• 2006

The objective of this study was to investigate the effects of supplementation of an antiobese functional formula (FC-GT) on body weight and lipid metabolism in rats fed a high-fat diet. Three groups of male Sprague-Dawley rats were fed different diets for 6 weeks: normal control (NC), high-fat (HF), and high-fat supplemented with powdered antiobese functional formula (FC-GT) (5% wt/wt) groups. Although body weight was not significantly different among the groups, relative weights of epididymal and perirenal white adipose tissues were significantly lower in the FC-GT group than in the HF group. FC-GT supplementation significantly lowered the plasma total cholesterol and triglyceride concentrations, whereas it elevated the ratio of HDL-C/total-C and improved the atherogenic index. Hepatic cholesterol and triglyceride concentrations were significantly lowered in the FC-GT group compared to the HF group. The accumulation of hepatic lipid droplets and the epididymal white adipocyte size of the FC-GT group were diminished compared to the HF group. Hepatic HMG-CoA reductase activity was significantly lower in the FC-GT group than in the HF group. Plasma GPT activity was significantly lowered in the FC-GT group compared to the HF group. Additionally, fecal weight was significantly increased in the FC-GT group than in the HF group. In addition, contents of fecal triglyceride and cholesterol were significantly higher in the FC-GT group compared to the other groups. The antioxidant activities of hepatic SOD, CAT, and GR were significantly increased in the FC-GT group compared to the HF group. Hepatic mARS and plasma mARS levels were significantly lowered in the FC-GT group compared to the NC group. Accordingly, we conclude that supplementation of FC-GT improves plasma and hepatic lipid levels in high-fat fed rats.

• Environmental Analysis Health and Toxicology
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• v.22 no.2 s.57
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• pp.147-156
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• 2007

Six week-old ICR mice were divided into four groups including NC, RC, RR and RS, then they were injected with sun ginseng (RS), red ginseng (RR) and saline (RC) intraperitoneally as an amount of 60mg/kg body weight at 1 hour, 12 hours and 36 hours before the whole body irradiation with 6.5Gy of X-ray. And the mice were sacrificed at nine days after the irradiation. The RS group were significant increase in the weight of spleen (p<0.05) and the numbers of endogenous spleen colony (p<0.001) and WBC (p<0.05) especially neutrophils, lymphocytes and monocytes in comparison with the RC group. The RR group were significant increase in the numbers of endogenous spleen colony (p<0.01) and WBC (p<0.05) especially neutrophils, lymphocytes and eosinophils in comparison with the RC group. The RS group exhibited a more increase in the weight of spleen and the number of endogenous spleen colony than the RR group. The values of ALT (alanine transaminase) and AST (aspartate transaminase) were significantly elevated (p<0.05) by radiation and they were significantly decreased (p<0.05) in the RS group to the values of the NC group. The value of TBARS(thiobarbituric acid reactive substance) was significantly elevated (p<0.01) by radiation and it was significantly decreased (p<0.05) in the RS group. And the values of SOD (superoxide dismutase) and CAT (catalase) were significantly increased (p<0.05) in the RS group in comparison with the RC group. Taken together the above results, sun ginseng demonstrated the protective effects on hepatocytes and immune and hematopoietic cells in mice exposed to medium dose of irradiation, and those radioprotective effects were a little higher or similar to the red ginseng.

• The Korean Journal of Physiology
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• v.25 no.2
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• pp.211-221
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• 1991

Although the existence of nerve cells which determine the activity of sympathetic nervous system in ventrolateral medulla is advocated recently, there are wide varieties on the location and function of them according to authors. Present study aimed to identify and characterize the medullospinal tract cells in rostral and caudal medulla of cats .which branch to the lateral horn of the upper thoracic spinal cord. Cats were anesthetized with ${\alpha}-chloralose$. The upper thoracic spinal cord and floor of the IVth ventricle were exposed. Medullospinal tract cells in rostral and caudal medulla were identified by anti-dromic stimulation of the intermediolateral nucleus in the upper thoracic cord and then the location and physiological characteristics of these cells were studied. A total of seventy cells in medulla had constant latency and responded to high frequency stimulation to thoracic cord. Among them fifty-six cells were identified as medullospinal tract cells either by collision with spontaneous activities or activities evoked by sciatic nerve stimulation(27/56), or by determining the refractory period (29/56). Thirty-one of these cells branched to the contralateral thoracic spinal cord, twenty-one cells to the ipsilateral side and remaining four cells branched to both sides. The conduction velocity of cells branching to the contralateral side was $29{\pm}2.9\;m/sec$ and that of cells to the ipsilateral side was $39.1{\pm}6.0\;m/sec$. When medulla was devided into two by a horizontal plane at 3 mm rostral to the obex, fifty-one among seventy cells were in the rostral medulla and nineteen were in the caudal medulla. The conduction velocities of these two groups were $21.6{\pm}1.0\;and\;33.3{\pm}3.9\;m/sec$, respectively. In this study, we confirmed the existence of two groups of medullospinal tract cells in rostral and caudal ventrolateral medulla, which branch to the lateral horn of thoracic cord and these cells have relatively few spontaneous activities and rapid conduction velocity, so we concluded that these cells are different from the previously known sympatho-related cells in ventrolateral medulla.