• Journal of radiological science and technology
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• v.41 no.5
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• pp.479-485
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• 2018

Radiologic technologists working at the second and third medical institutions are classified as radiation-related workers and radiation workers according to their working departments, and are subject to double regulation by the Ministry of Health and Welfare and the Nuclear Safety Commission. We will try to understand the system of dualization and to understand the investigation of recognition. The dualized system of radiation-related workers and radiation workers includes the difference in name and terminology, the effective dose limit, the maintenance education and training of radiologic technologists, the period of medical examination, the radiation zone, dose of the woman whose pregnancy is confirmed in radiologic technologists, the qualification criteria of the safety officer, and the period of the regular inspection of the radiological equipment. In the questionnaire survey on the dualization system, there were various items showing significant differences between the radiation-related workers and radiation workers Overall, the radiation workers were more aware of the radiation workers' education and related terms than the radiation-related workers.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.80-80
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• 2003

Insulin-dependent or Type 1 diabetes mellitus (IDDM) has been associated with an increased severity of periodontal disease. Since periodontal ligament (PDL) cells play a significant role in maintenance and regeneration of mineralized tissue, the success of procedures, such as guided tissue regeneration, is directly related to the ability of these cells to augment mineralized tissue. In this study, we investigated the time- and dose-dependent effect of high glucose on the proliferation and collagen synthesis of human periodontal ligament (PDL) cells. PDL cells were treated with high glucose (22mM, 33mM, 44mM) for 1 or 2 days. High glucose significantly inhibited proliferation of PDL cells as a time- and dose-dependent manner as evidenced by MTT assay. PDL cells were cultured in high glucose media (22mM, 33mM, 44mM) for 24 h. The ratio of collagen content to total protein was evaluated, and the gene expression of type I collagen was assessed by RT - PCR. The high concentration of glucose inhibited collagen synthesis, a marker of bone formation activity. This study indicated high glucose concentration could alter the metabolism of periodontal ligament cell, leading to alveolar bone destruction.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1995.10a
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• pp.115-124
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• 1995

The purpose of the present study was to address whether the in vivo noradrenergic neural activities in the locus coeruleus are involved in the regulation of blood pressure. Two groups of the animals were prepared, 1) SHR and 2) age-matched normotensive control, WKY. At the age of 6 and 16 weeks, blood pressure and the releases of NE from the locus coeruleus in SHR and KWY were measured by in vivo microdialysis at three different conditions: 1) normal, 2) elevated state of blood pressure by systemic injected phenylephrine and 3) increased state of neural activity by perfused phenylephrine into the locus coeruleus. The basal release of NE of SHR were significantly higher than that of WKY, Phenylephrine treatment caused elevation of blood pressure in both SHR and WKY in dose-dependent manner. Following phenylephrine injection, the releases of NE from the locus coeruleus of SHR were significantly decreased, whereas the significant change of NE in WKY was observed in the highest dose of phenylephrine. Phenylephrine perfusion into the locus coeruleus through microdialysis probe caused pressor responses and the pressor response in SHR was greater compared with that in WKY. The results from the present study suggests that the noradrenergic nervous system in the locus coeruleus may contribute as one of the development and maintenance factors for hypertension in SHR.

• The Journal of Internal Korean Medicine
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• v.20 no.1
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• pp.73-82
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• 1999

Nitric oxide (NO) is now recognized as a mediator of several biological and immunological functions, but unlike classical neurotransmitters. NO simply diffuse of the postsynaptic cells and around affecting cells. Taraxacum officinale (Compositae) has been used for maintenance of vitality, and they still occupy an important place in the traditional Korean medicine. We have examined that the effect of Taraxacum officinale water extract on NO synthesis in microglial cells of murine's brain, using the Griess method. And this study was evident that Taraxacum officinale did not induce NO production without recombinant interferon gamma ($rIFN-{\gamma}$), whereas Taraxacum officinale (10-1000 g/ml) with $rIFN-{\gamma}$ effectively produced NO in microglial cells of brain. As result. NO production in microglial cells increased most significantly in dose of 100 g/ml of the Taraxacum officinale and the production of NO was dependent on the dose of Taraxacum officinale, NG-monomethyl-L-arginine, competitive inhibitor of NO synthase, reduced the NO production by Taraxacum officinale stimulation with $rIFN-{\gamma}$ in microglial cells of murine. The effect of Taraxacum officinale was mainly dependent on Taraxacum officinale-induced tumor necrosis factor- secretion. Conclusively, this study suggested that Taraxacum officinale stimulate NO production at microglial cells in brain, which may be an important factor for mediating immune and neuroendocrinologic regulation in nervous system.

• Magazine of the Korean Society of Agricultural Engineers
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• v.45 no.2
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• pp.126-137
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• 2003

The feasibility study of UV-disinfection system was performed for disinfection of effluent from wastewater treatment plant. Three low-pressure UV lamps of 17, 25, and 41 W were examined with various flow rates. Low-pressure UV lamps of 17W were examined with various turbidity, DOM (dissolved organic matter), and SS (suspended solid). The pilot plant was a flow-through type UV-disinfection system, and the range of exposure time varied from 5 to 40 seconds, turbidity from 0 to 40 NTU, DOM from 0 to 30 mg/L, and SS from 10 to 40 mg/L. The 41W lamp demonstrated complete disinfection showing no survival ratio in all the experimental conditions, and generally 17W and 25W lamps also showed high removal ratio over 97%. For the same UV dose (UV intensity times exposure time), high intensity-short exposure conditions showed better disinfection efficiency than low intensity-long exposure conditions. While the effects of turbidity and DOM were not apparent, the effects of SS was significant on the disinfection efficiency which indicates that SS control before UV-disinfection appears to be necessary to increase removal efficiency. Considering characteristics of effluent from existing wastewater treatment plants, cost-effectiveness, stable performance, and minimum maintenance, the flow-through type UV-disinfection system with high intensity and low-pressure lamps was thought to be a competitive disinfection system for wastewater reclamation.

• YAKHAK HOEJI
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• v.53 no.2
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• pp.83-88
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• 2009

Warfarin is the most widely used oral anticoagulant in the world but maintenance of proper therapeutic range and prevention of adverse drug events always need to be careful. Especially, in Korea, warfarin dosing for patients with cerebral infarction is currently based on the nomogram which is done by foreign clinical trials not for the Korean. Therefore we evaluate warfarin dose of patients in the neurology and eventually get the base data of warfarin nomogram for Korean with stroke. We performed this study retrospectively on reviewing the medical charts to evaluate the prescribed loading dose (LD) and maintenance dose (MD) of warfarin and each responding International Normalized Ratio (INR) with any bleeding adverse drug reaction including of patient's characteristics for total 75 patients with stroke in the department of neurology of Kangnam ST. Mary's Hospital from January 2005 to June 2008. All evaluated patients should not be treated with warfarin in the past at all and should be initiated warfarin therapy first.ly at this time. All evaluated patients were divided as two classes by wafarin LD which is; 1) HDG - a high loading dosing group prescribed over 5mg, and 2) LDG - a low loading dosing group prescribed 5mg or below. As a result, average LD was $9.34{\pm}0.22$ mg (p=0.000) in HDG and $4.25{\pm}0.39$ mg (p=0.000) in LDG. Average baseline INR was $0.91{\pm}0.05$ (p=0.161) in HDG and $1.26{\pm}0.14$ (p=0.002) in LDG. On the first and second week, daily MD was $4.21{\pm}0.14$ mg (p=0.000) and $2.96{\pm}0.19$ mg (p=0.696) in HDG and also in LDG, $2.95{\pm}0.29$ mg (p=0.000) and $3.14{\pm}0.36$ mg (p=0.696). Also average reacting daily INR was respectively $2.53{\pm}0.12$ (p=0.141) and $2.51{\pm}0.16$ (p=0.678) in HDG, and in LDG, $2.11{\pm}0.17$ (p=0.141) and $2.42{\pm}0.14$ (p=0.678). After the second week, INR was not measured in regularly. Also most of underlying diseases were hypertension (n=38), diabetes mellitus (n=14), dyslipidemia (n=8) in order. Four ADRs with simple hemorrhage were occurred and those were due to drug interaction by comedication. In the conclusion, proper starting LD for Korean with stroke is 10 mg if baseline INR is around 1.0 or 5 mg if over 1.3. Proper MD need to be more evaluated in the future for setting up warfarin nomogram to make prospective study.

• Journal of radiological science and technology
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• v.39 no.4
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• pp.643-649
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• 2016

When a cyclotron produces $^{18}F^-$, accelerated protons interact with metal parts of the cyclotron machine and induces radioactivity. Especially, the target window and chamber of the target assembly are the main parts where long-lived radionuclides are generated as they are incident by direct beams. It is of great importance to identify radionuclides induced in the target assembly for the safe operation and maintenance of a cyclotron facility. In this study, we analyzed major radionuclides generated in the target assembly by an operation of the Cyclotron 18/9 machine and measured dose rates after the operation to establish the radiation safety guideline for operators and maintenance personnel of the machine. Gamma spectroscopy with HPGe was performed on samples from the target chamber and Havar foil target window to identify the radionuclides generated during the operation for production of $^{18}F^-$- isotope and their specific activity. Also, the dose rates from the target were measured as a function of time after an operation. These data will help improve radiological safety of operating the cyclotron facilities.

• Journal of Radiation Protection and Research
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• v.34 no.3
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• pp.129-136
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• 2009

During the maintenance period at Korean nuclear power plants, internal exposure of radiation workers occurred by the inhalation of $^{131}I$ released to the reactor building when primary system opened. The internal radioactivity of radiation workers contaminated by $^{131}I$ was measured using a whole body counter. Intake estimation and the calculation of committed effective dose were also conducted conforming to the guidance of internal dose assessments from publications of International Commission on Radiological Protection. Because the uptake and excretion of $^{131}I$ in a body occur quickly and $^{131}I$ is accumulated in the thyroid gland, the estimated intakes showed differences depending on the counting time after intake. In addition, since ICRP publications do not provide the intake retention fraction (IRF) for whole body of $^{131}I$, the IRF for thyroid was substitutionally used to calculate the intake and subsequently this caused more error in intake estimation. Thus, intake estimation and the calculation of committed effective dose were conducted by manual calculation. In this study, the IRF for whole body was also calculated newly and was verified. During this process, the estimated intake and committed effective dose were reviewed and compared using several computer codes for internal dosimetry.

• Journal of Gastric Cancer
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• v.23 no.2
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• pp.315-327
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• 2023

Purpose: Oxaliplatin, a component of the capecitabine plus oxaliplatin (XELOX) regimen, has a more favorable toxicity profile than cisplatin in patients with advanced gastric cancer (GC). However, oxaliplatin can induce sensory neuropathy and cumulative, dose-related toxicities. Thus, the capecitabine maintenance regimen may achieve the maximum treatment effect while reducing the cumulative neurotoxicity of oxaliplatin. This study aimed to compare the survival of patients with advanced GC between capecitabine maintenance and observation after 1st line XELOX chemotherapy. Materials and Methods: Sixty-three patients treated with six cycles of XELOX for advanced GC in six hospitals of the Catholic University of Korea were randomized 1:1 to receive capecitabine maintenance or observation. The primary endpoint was progression-free survival (PFS), analyzed using a two-sided log-rank test stratified at a 5% significance level. Results: Between 2015 and 2020, 32 and 31 patients were randomized into the maintenance and observation groups, respectively. After randomization, the median number of capecitabine maintenance cycles was 6. The PFS was significantly higher in the maintenance group than the observation group (6.3 vs. 4.1 months, P=0.010). Overall survival was not significantly different between the 2 groups (18.2 vs. 16.5 months, P=0.624). Toxicities, such as hand-foot syndrome, were reported in some maintenance group patients. Maintenance treatment was a significant factor associated with PFS in multivariate analysis (hazard ratio, 0.472; 95% confidence interval, 0.250-0.890; P=0.020). Conclusions: After 6 cycles of XELOX chemotherapy, capecitabine maintenance significantly prolonged PFS compared with observation, and toxicity was manageable. Maintenance treatment was a significant prognostic factor associated with PFS.

• Journal of Dental Anesthesia and Pain Medicine
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• v.18 no.5
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• pp.295-300
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• 2018

Background: Removal of the plate following Le Fort I osteotomy and BSSO (bilateral sagittal split osteotomy) is a common procedure. However, patients who undergo plate removal experience intense pain and discomfort. This study investigated the half-maximal effective concentration ($Ce_{50}$) of remifentanil in the prevention of plate removal pain under sedation using dexmedetomidine. Methods: The study evaluated 18 patients, between 18 and 35 years of age, scheduled for elective surgery. Remifentanil infusion was initiated after sedation using dexmedetomidine, and started at a dose of 1.5 ng/mL on the first patient via target-controlled infusion (TCI). Patients received a loading dose of $1.0{\mu}g/kg$ dexmedetomidine over 10 min, followed by a maintenance dose of $0.7{\mu}g/kg/h$. When the surgeon removed the plate, the patient Modified Observer's Assessment of Alertness/Sedation (MOAA/S) score was observed. Results: The Ce of remifentanil ranged from 0.9 to 2.1 ng/mL for the patients evaluated. The estimated effect-site concentrations of remifentanil associated with a 50% and 95% probability of reaching MOAA/S score of 3 were 1.28 and 2.51 ng/mL, respectively. Conclusion: Plate removal of maxilla can be successfully performed without any pain or adverse effects by using the optimal remifentanil effect-site concentration ($Ce_{50}$, 1.28 ng/mL; $Ce_{95}$, 2.51 ng/mL) combined with sedation using dexmedetomidine.