• Journal of Environmental Science International
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• v.31 no.3
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• pp.227-235
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• 2022

In this study, a biodegradation model of based on molecular cellulose was established. It is a mathematical, kinetic model, assuming that two major enzymes randomly break glycosidic bonds of cellulose molecules, and calculates the number of molecules by applying the corresponding probability and degradation reaction coefficients. Model calculations considered enzyme dose, cellulose chain length, and reaction rate constant ratio. Degradation increased almost by two folds with increase of temperature (5℃→25℃). The change of degradation was not significant over the higher temperatures. As temperature increased, the degradation rate of the molecules increased along with higher production of shorter chain molecules. As the reaction rates of the two enzymes were comparative the degree of degradation for any combinations of enzyme application was not affected much. Enzyme dose was also tested through experiment. While enzyme dose ranged from 1 mg/L to 10 mg/L, the gap between real data and model calculations was trivial. However, at higher dose of those enzymes (>15 mg/L), the experimental result showed the lower concentrations of reductive sugar than the corresponding model calculation did. We determined that the optimal enzyme dose for maximum generation of reductive sugar was 10 mg/L.

• Korean Journal of Radiology
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• v.1 no.2
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• pp.91-97
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• 2000

Objective: To determine whether the time-intensity curves acquired by test and main dose contrast injections for MR angiography are similar. Materials and Methods: In 11 patients, repeated contrast-enhanced 2D-turbo-FLASH scans with 1-sec interval were obtained. Both test and main dose timeintensity curves were acquired from the abdominal aorta, and the parameters of time-intensity curves for the test and main boluses were compared. The parameters used were arterial and venous enhancement times, arterial peak enhancement time, arteriovenous circulation time, enhancement duration and enhancement expansion ratio. Results: Between the main and test boluses, arterial and venous enhancement times and arteriovenous circulation time showed statistically significant correlation (p < 0.01), with correlation coefficients of 0.95, 0.92 and 0.98 respectively. Although the enhancement duration was definitely greater than infusion time, reasonable measurement of the end enhancement point in the main bolus was impossible. Conclusion: Only arterial and venous enhancement times and arteriovenous circulation time of the main bolus could be predicted from the test-bolus results. The use of these reliable parameters would lead to improvements in the scan timing method for MR angiography.

• Journal of the Korean Society of Radiology
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• v.6 no.6
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• pp.499-505
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• 2012

The purpose of this study was to find out the difference of radiation dose value through energy, exposure number, fluoroscopy time, the number of days of exposed scatter X-ray when TLD and OSLD is used in diagnostic radiology. The difference of value were measured by relative ratio and interval. Energy makes high relative ratio of TLD($1.81{\pm}0.41$) than OSLD($1.40{\pm}0.26$), exposure number makes high of OSLD($1.40{\pm}0.26$) than TLD($2.10{\pm}0.10$). There are no significant differences between relative ratio of TLD and OSLD in fluoroscopy time and the number of days of exposed scatter X-ray. But interval of relative ratio in the number of days of exposed scatter X-ray was narrowed in less 0.2. That means, the measurement of scatter X-ray could more confident in TLD and OSLD than the measurement of direct ray. In conclusion, we have to recognize the relative ratio of TLD and OSLD could be vary depending on exposed condition of radiation. And in some cases, double test of TLD and OSLD get more creditable results of dose value.

• The Journal of Internal Korean Medicine
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• v.20 no.1
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• pp.167-180
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• 1999

Cervus elaphus, being known to reinforce Kidney, have tested to study the effects concerning damages of brain tissue induced by lipid peroxidation. In vitro, the level of lipid peroxide in brain tissue was decreased proportinally according to dose by Cervus elaphus extract solution for aqua-acupuncture (CESAA). It was much more decreased, when lipid peroxidation was induced with Fe(II). And, it was seen proportinally decrease according to the dose of CESAA on xanthine oxidase activities and type conversion ratio. However, I can not find special changes about aldehyde oxidase activities. And, I had observed the effects of CESAA on damages of rat's brain following ischemia and reflow. Before ischemia was caused, CESAA was applied 0.2 ml per 250 g through femoral vein in ischemia and reflow group and normal sailine was applied in normal group. Ischemia was caused by cervical artery's clamp for 30 min and reflowed by clamp remove after 15 min. It was increased on the content of lipid peroxidation, activies and type conversion ratio of xanthine oxidase following ischemia and reflow. However, they were decreased when CESAA was pre-appllied. However, it could not seen special changes on aldehyde oxidase activities, either. In conclusion. CESAA recovers the damage of brain due to ischemia and reflow by decreasing the lipid peroxidation through decreasing of xanthine oxidase activies and type conversion ratio.

• Journal of Physiology & Pathology in Korean Medicine
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• v.34 no.2
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• pp.75-80
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• 2020

In this study, we investigated the dose-dependent effects of mixtures of Atractylodes macrocephala (AM) and Amomum villosum (AV) water extracts in a ratio of 3:1 on high fat diet (HFD)-induced obesity model. Oral administration of various concentrations with mixtures of AM and AV extracts in a ratio of 3:1 for 6 weeks inhibited HFD-induced increases of body, liver and epididymal fat weights in a dose-dependent fashions. Those effects may be mediated by decreased expressions of lipogenesis-related genes such as acetyl coA carboxylase (ACC) and fatty acid synthase (FAS) in liver. Also, increase of insulin and decrease of adiponectin in serum by HFD supply were inhibited by three different dosages of mixtures of AM and AV extracts in a ratio of 3:1. HFD supply induced increases of serum total cholesterol, triglyceride and LDL cholesterol. However, hyperlipidemia was significantly decreased in dose-dependent manners by treatment with mixtures of AM and AV extracts. Based on the results of the present study, hypolipidemic and anti-obesity effects by mixtures of AM and AV extracts were found in HFD-induced obesity model. Further clinical investigation is needed to develop anti-obesity therapeutic or preventive agents by using mixtures of AM and AV extracts.

• Journal of Preventive Medicine and Public Health
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• v.27 no.3 s.47
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• pp.569-579
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• 1994

The genetically determined ability to metabolize debrisoquine (DBR) is related to risk of lung cancer and DBR hydroxylation exhibits wide inter-individual variation. In this study, 100 korean adults were tested for their ability to metabolize DBR. The DBR metabolic phenotype were determined by metabolic ratio (MR, DBR / 4-HDBR) which is the percent dose excreted as unchanged DBR divided by the percent dose excreted as 4-hydroxyebrisoquine(4-HDBR) in a aliquot of an eight hour urine sample, after 10mg DBR test dose administration. Analysis was performed on a capillary gas chromatograph fitted with electron capture detector. The results were as follows; 1 Geometric mean of DBR MR was 0.32 in male,0.27 in female,0.30 in total and the distribution of log (MR) was seemed to follow normal distribution. 2. Metabolic ratio of DBR was higher in non-smoker and non-drinker than in smoker and drinker without any statistically significant difference. 3. None of personal factors was significantly related to DBR MR except age. 4. The DBR metabolic phenotype was extensive metabolizer(EM) 93, intermediate metabolizer(IM) 7 by traditional method and EM 98, IM 3 by Caporaso's method. The poor metabolizer (PM) phenotype was not found by either method. 5. Maximal expected PM phenotype was 0.36% by traditional method and 0.04% by Caporaso's method.

• Korean Journal of Acupuncture
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• v.39 no.2
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• pp.54-62
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• 2022

Objectives : The purpose of this study was to evaluate the potential of the test substance, SU-Eohyeol Pharmacopuncture (SUEP), to induce micronuclei in bone marrow cells of Sprague-Dawley (SD) Rats. Methods : The dose range preliminary study was performed first. 1 ml/animal was selected as the high dose of this study. Two additional lower dose levels (0.5 and 0.25 ml/animal) were produced by applying a geometric ratio of 2. In addition, the positive and negative control groups were set. Then, after intramuscular administration (1 ml/animal) of SUEP to 8-week-old male SD rats, an in vivo micronucleus test was performed to evaluate the induction of micronuclei in SD rat bone marrow cells. Results : As a result of the main study, the incidence of micronucleated polychromatic erythrocytes (MNPCE) in polychromatic erythrocytes (PCE) in the test substance SUEP groups was not statistically significantly different from the negative control group. In addition, the ratio of PCE to total erythrocytes in the test substance SUEP groups was not statistically significantly different from the negative control group. In the positive control group, the incidence of MNPCE in PCE was statistically significantly increased when compared to the negative control group. The ratio of PCE to total erythrocytes in the positive control group was not statistically significantly different from the negative control group. Conclusions : Based on these results, the test substance, SUEP, did not have any potential to induce micronuclei formation in bone marrow cells of rats under the conditions of this study.

• Korean Journal of Clinical Pharmacy
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• v.24 no.3
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• pp.193-198
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• 2014

Objective: This study was conducted to compare the adherence, clinical and economical utility of fixed-dose combination tablets of sitagliptin/metformin with concomitant administration of sitagliptin and metformin in patients with type 2 diabetes mellitus. Methods: Adherence was measured as the medication possession ratio (MPR) of ${\geq}80%$, and MPR was calculated as the number of total prescription days divided by the total treatment period. Hemoglobin $A_{1C}$ ($HbA_{1c}$) differences between baseline and predetermined periods were analyzed. Proportions of patients who achieved $HbA_{1c}$ less than 6.5% for three or more consecutive times were compared. To evaluate cost-effectiveness, prices of sitagliptin, metformin and sitagliptin/metformin tablets were investigated. Results: More than 90% of patients showed adherence in both groups (92.0% in fixed-dose combination group vs 95.9% in concomitant administration group), and there was no statistically significant difference (P = 0.113). Proportion of patients with HbA1c less than 6.5% for three or more consecutive times tended to be somewhat higher in fixed dose combination group than in concomitant administration group without a statistically significant difference (32.6% vs. 28.0%, P = 0.344). Total price of metformin and sitagliptin was cheaper up to 222 KRW in the case of fixed-dose combination tablets compared to the case of concomitant administration. Conclusion: The sitagliptin/metformin fixed-dose combination tablet had a similar patient adherence and was not significantly different in efficacy to the concomitant administration of each component. In terms of drug prices, fixed-dose combination tablets were cheaper than concomitant administration of each tablet.

• Journal of Radiation Protection and Research
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• v.43 no.2
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• pp.59-65
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• 2018

Background: We analyzed changes in the doses, structure volumes, and dose-volume histograms (DVHs) when data were transferred from one commercial treatment planning system (TPS) to another commercial TPS. Materials and Methods: A total of 22 volumetric modulated arc therapy (VMAT) plans for nasopharyngeal cancer were generated with the Eclipse system using 6-MV photon beams. The computed tomography (CT) images, dose distributions, and structure information, including the planning target volume (PTV) and organs at risk (OARs), were transferred from the Eclipse to the MRIdian system in digital imaging and communications in medicine (DICOM) format. Thereafter, DVHs of the OARs and PTVs were generated in the MRIdian system. The structure volumes, dose distributions, and DVHs were compared between the MRIdian and Eclipse systems. Results and Discussion: The dose differences between the two systems were negligible (average matching ratio for every voxel with a 0.1% dose difference criterion = $100.0{\pm}0.0%$). However, the structure volumes significantly differed between the MRIdian and Eclipse systems (volume differences of $743.21{\pm}461.91%$ for the optic chiasm and $8.98{\pm}1.98%$ for the PTV). Compared to the Eclipse system, the MRIdian system generally overestimated the structure volumes (all, p < 0.001). The DVHs that were plotted using the relative structure volumes exhibited small differences between the MRIdian and Eclipse systems. In contrast, the DVHs that were plotted using the absolute structure volumes showed large differences between the two TPSs. Conclusion: DVH interpretation between two TPSs should be performed using DVHs plotted with the absolute dose and absolute volume, rather than the relative values.

• Nuclear Engineering and Technology
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• v.52 no.10
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• pp.2410-2414
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• 2020

Heavy ions have a high potential for destroying deep tumors that carry the highest dose at the peak of Bragg. The peak caused by a single-energy carbon beam is too narrow, which requires special measures for improvement. Here, carbon-12 (¹²C) ion with different energies has been used as a source for calculating the dose distribution in the water phantom, soft tissue and bone by the code of Monte Carlobased FLUKA code. By increasing the energy of the initial beam, the amount of absorbed dose at Bragg peak in all three targets decreased, but the trend for this reduction was less severe in bone. While the maximum absorbed dose per bone-mass unit in energy of 200 MeV/u was about 30% less than the maximum absorbed dose per unit mass of water or soft tissue, it was merely 2.4% less than soft tissue in 400 MeV/u. The simulation result showed a good agreement with experimental data at GSI Darmstadt facility of biophysics group by 0.15 cm average accuracy in Bragg peak positioning. From 200 to 400 MeV/u incident energy, the Bragg peak location increased about 18 cm in soft tissue. Correspondingly, the bone and soft tissue revealed a reduction dose ratio by 2.9 and 1.9. Induced neutrons did not contribute more than 1.8% to the total energy deposited in the water phantom. Also during ¹²C ion bombardment, secondary fragments showed 76% and 24% of primary 200 and 400 MeV/u, respectively, were present at the Bragg-peak position. The combined treatment of carbon ions with neutron or electron beams may be more effective in local dose delivery and also treating malignant tumors.