• Journal of the Korea Convergence Society
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• v.9 no.7
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• pp.87-93
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• 2018

In this study, $^{99m}Tc$, $^{123}I$, $^{201}Tl$, $^{18}F$, and $^{131}I$, which are widely used in nuclear medicine, were transmitted through a bismuth shield. We investigated the shielding rates according to the type of radioisotope and the distance of measurement. For the experiment, 6 sheets of lead equivalent 0.25 mm Pb of bismuth shielding material were stacked one by one up to 1.50 mm as the thickness increased. The distance was 30 cm, 50 cm, and 100 cm, and the transmission dose was measured. As a result, the shielding rates was measured as the thickness increased, and the measured value decreased as the distance increased. The shielding rate of $^{123}I$ and $^{201}Tl$ was higher than $^{99m}Tc$, $^{18}F$ and $^{131}I$ showed lower shielding effect when there is a shielding material than when there is no shielding material due to high energy and ${\beta}$ rays. Based on the results of experiments, it would be helpful to reduce the exposure of nuclear medicine workers and to manage the exposure if bismuth shields are used depending on the type of radioisotope.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.11 no.3
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• pp.245-251
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• 2013

The energy band and the G-factor method were compared to determine the exposure rate from the measured spectrum using a NaI(Tl) scintillation detector. First, G-factors of a 3"${\Phi}X3$" NaI(Tl) detector mounted to a EFRD 3300, which means the environmental radiation monitor, in Korea Atomic Energy Research Institute (KAERI) were calculated for several directions of incident photons through the MCNP modeling, and the optimum G-factor applicable to that monitor was then determined by comparing the results both the energy band method and the G-factor method. The results for these spectrometric determinations were also compared with the dose rate from a HPIC radiation monitor around a EFRD 3300. The measured value at the EFRD 3300 based on a 3"${\Phi}X3$" NaI(Tl) detector was $7.7{\mu}R/h$ and its difference was shown about $3{\mu}R/h$, when compared with the results from a HPIC radiation moditor. Since a HPIC is known to be able to measure cosmic rays with the relatively high energy, the difference between them was caused by cosmic rays which were not detected in a 3"${\Phi}X3$" NaI(Tl) detector.

• Radiation Oncology Journal
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• v.11 no.2
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• pp.369-376
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• 1993

226 patients with carcinoma of the uterine cervix treated with curative radiation therapy at the Department of Therapeutic Radiology, Dongsan hospital, Keimyung university, School of medicine, from July,1988 to May,1991 were evaluated. The patients with all stages of the disease were included in this study. The maximum and mean follow up durations were 60 and 43 months. The radiation therapy consisted of external irradiation to the whole pelvis (2700~4500 cGy) and boost parametrial doses (for a total of 4500~6300 cGy)with midline shild $(4{\times}10\;cm),$ and combined with intracavitary irradiation (5700~7500 cGy to point A). The distribution of patients according to the stage was as follows: stage IB 37 $(16.4\%),$ stage IIA 91 $(40.3\%),$ stage IIB 58 $(25.7\%),$ stage III 32 $(13.8\%),$ stage IV 8 $(3.5\%).$ The overall failure rate was $23.9\%$ (54 patients). The failure rate increased as a function of stage from $13.5\%$ in stage IB to $15.4\%$ in stage IIA, $25.9\%$ in stage IIB, $46.9\%$ in stage III, and $62.5\%$ in stage UV. The pelvic failure alone were 32 patients and 11 patients were as a components of other failure, and remaining 11 patients had distant metastasis only. Among the 43 patients of locoregional failure,28 patients were not controlled initially and in other words nearly half of total failures were due to residual tumor. The mean medial paracervical (point A) doses were 6700 cGy in stage IIB,7200 cGy in stage IIA,7450 cGy in stage IIB,7600 cGy in stage III and 8100 cGy in stage IV. The medial paracervical doses showed some correlation with tumor control rate in early stage of disease (stage Ib, IIA), but there were higher central failure rate in advanced stage in spite of higher paracervical doses. In advanced stage, failure were not reduced by simple increment of paracervical doses. To improve a locoregional control rate in advanced stages, it is necessary to give additional treatment such as concomitant chemoradiation.

• Radiation Oncology Journal
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• v.17 no.2
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• pp.113-119
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• 1999

Purpose : To evaluate possible acute toxicity and early response of concurrent radiation therapy and low dose daily cisplatin as a radiosensitizer in patients with locally advanced uterine cervical carcinomas. Materials and Method : From December 1996 to January 1999, 38 previously untreated Patients with locally advanced squamous cell carcinoma of the uterine cervix (from stage IIB to stage IIIB) were treated at Inha University Hospital. All patients underwent standard pretreatment staging Procedures after the initial evaluation by gynecologists and radiation oncologists. Sixteen Patients with huge cervical mass (>4 cm) were submitted to the group treated with concurrent radiation therapy and low dose daily cisplatin while the remainder was treated with radiation therapy alone. Radiation therapy consisted of 4500 cGy external beam irradiation to whole pelvis (midline block after 3000 cGy), 900$\~$1000 cGy boost to involved parametrium, and high dose-rate intracavitary brachytherapy (a total dose of 3000$\~$3500 cGy/500 cGy per fraction to point A, twice per week). In the group treated with low dose cisplatin concurrently, 10 mg of daily intravenous cisplatin was given from the 1st day of radiation therapy to the 20th day of radiation therapy. Acute toxicity was measured according to expanded common toxicity criteria of the NCI (C) Clinical Trials. Early response data were analyzed at minimum 4 weeks' follow-up after completion of the treatment protocol. Results: Hematolgic toxici쇼 was more prominent in patients treated with radiation therapy and cisplatin. Six of 16 patients (37.5$\~$) treated with radiation therapy and cisplatin and one of 22 patients (4.5$\~$) treated with radiation therapy alone experienced grade 3 leukopenia. In Fisher's exact test, there was statistically significant difference between two groups regarding leukopenia (P=0.030). There was no apparent difference in the frequency of gastrointestinal and genitourinary toxicity between two groups (P=0.066). Three of 16 patients (18.7$\~$) treated with radiation therapy and cisplatin and two of 22 patients (9.1$\~$) treated with radiation therapy alone experienced more than 5 kg weight loss during the treatment. There was no statistically significant difference on weight loss between two groups (P=0.63). Two patients on each group were not evaluable for the early response because of incomplete treatment. The complete response rate at four weeks' follow-up was 80$\~$(16/20) for the radiation therapy alone group and 78$\~$ (11/14) for the radiation therapy and cisplatin group. There was no statistically significant difference in early response between two treatment groups (P=0.126). Conclusion : This study led to the conclusion that the hematologic toxicity from the treatment with concurrent radiation therapy and low dose daily cisplatin seems to be more prominent than that from the treatment of radiation therapy alone. There was no grade 4 hematologic toxicity or mortality in both groups. The hematologic toxicity in both treatment groups seems to be well managable modically. Since the risk factors were not balanced between two treatment groups, the direct comparison of early response of both groups was not possible. However, preliminary results regarding early response for patients with bulky cervical tumor mass treated with radiation therapy and low dose daily cisplatin was encouraging. Longer follow-up is necessary to evaluate the survival data. A phase III study is needed to evaluate the efficacy of concurrent daily low dose cisplatin with radiation therapy in bulky cervical cancer.

• Radiation Oncology Journal
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• v.19 no.1
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• pp.66-73
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• 2001

Purpose : For the research of Boron Neutron Capture Therapy (BNCT), fast neutrons generated from the MC-50 cyclotron with maximum energy of 34.4 MeV in Korea Cancer Center Hospital were moderated by 70 cm paraffin and then the dose characteristics were investigated. Using these results, we hope to establish the protocol about dose measurement of epi-thermal neutron, to make a basis of dose characteristic of epi-thermal neutron emitted from nuclear reactor, and to find feasibility about accelerator-based BNCT. Method and Materials : For measuring the absorbed dose and dose distribution of fast neutron beams, we used Unidos 10005 (PTW, Germany) electrometer and IC-17 (Far West, USA), IC-18, ElC-1 ion chambers manufactured by A-150 plastic and used IC-l7M ion chamber manufactured by magnesium for gamma dose. There chambers were flushed with tissue equivalent gas and argon gas and then the flow rate was S co per minute. Using Monte Carlo N-Particle (MCNP) code, transport program in mixed field with neutron, photon, electron, two dimensional dose and energy fluence distribution was calculated and there results were compared with measured results. Results : The absorbed dose of fast neutron beams was $6.47\times10^{-3}$ cGy per 1 MU at the 4 cm depth of the water phantom, which is assumed to be effective depth for BNCT. The magnitude of gamma contamination intermingled with fast neutron beams was $65.2{\pm}0.9\%$ at the same depth. In the dose distribution according to the depth of water, the neutron dose decreased linearly and the gamma dose decreased exponentially as the depth was deepened. The factor expressed energy level, $D_{20}/D_{10}$, of the total dose was 0.718. Conclusion : Through the direct measurement using the two ion chambers, which is made different wall materials, and computer calculation of isodose distribution using MCNP simulation method, we have found the dose characteristics of low fluence fast neutron beams. If the power supply and the target material, which generate high voltage and current, will be developed and gamma contamination was reduced by lead or bismuth, we think, it may be possible to accelerator-based BNCT.

• The Journal of Korean Medicine
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• v.25 no.4
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• pp.1-7
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• 2004

Objective : This study was designed to examine the effects of orally administered Prunus persica water extract (PPE), which is used as herbal medicine, for treatment of Yu Xue (stasis of blood) and tacrine on the basal concentration of extracellular acetylcholine in the hippocampus of rats. Methods: To investigate the effects of PPE and tacrine on concentration of extracellular acetylcholine in the hippocampus of rats, the microdialysis technique, under the same experimental conditions, was used. And we used male Wistar rats which were 7 weeks of age and 210-290 g. PPE was extracted with boiling water, and the rats were anesthetized with pentobarbital Na. Their skulls were exposed and a hole was drilled for implantation of a microdialysis probe. In order to increase the recovery of acetylcholine, a probe with a long membrane was used. One day after surgery, the microdialysis probe was perfused with Ringer's solution at a flow rate of 1.5 l/min. The acetylcholine concentration in dialysis samples was measured by high-performance liquid chromatography (HPLC) with electrochemical detection. AChE activity was measured using the radiometric method, as described by Sherman. Results : The comparative effects of PPE and tacrine on hippocampal extracellular acetylcholine concentration was that these cholinesterase inhibitors produced dose-dependent increases in the extracellular acetylcholine concentration. And the effect of PPE and tacrine on rat brain AChE activity was that PPE produced maximal inhibition at 1 h after administration, when AChE activity was 44% of the intact level. AChE activity gradually recovered thereafter, and reached 78% of the intact level at 12 h after administration. Conclusion : In this study, PPE has a potent activity and a long-lasting effect on the central cholinergic system, in terms of the basal concentration of extracellular acetylcholine in the hippocampus and the AChE activity in the brain of rats. And oral administration of PPE increased dose-dependently the basal concentration of extracellular acetylcholine in the hippocampus of rats. PPE may be one of the more useful cholinesterase inhibitors for the treatment of Alzheimer's disease.

• Korean Journal of Veterinary Research
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• v.43 no.2
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• pp.195-202
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• 2003

Chitosan is known to have antibacterial, antitumorogenic, hypolipidemic and immunopotentiating activities, hence finding diverse uses as a component in varying functional foodstuffs. However, some investigators reported it caused mineral absoiption inhibition and excess coagulation. From the chemical viewpoint, conventional chitosans are high-molecule polymers lacking water solubility, which could be related with their possible toxicity. A newly developed low- molecule water soluble chitosan is thought to have low toxicity compared to conventional chitosans. But no investigation was carried out to evaluate its toxicity. In this study, a 28-day subacute oral toxicity study of the water-soluble chitosan was performed in Sprague-Dawley rats of both sexes. Each 36 male and female rats were orally administered with 500, 1,000 and 2,000 mg/kg/day for 28 consecutive days, respectively. Clinical parameters (growth rate, feed and water consumption, daily inspection, urine analysis) during the 28 days indicated the water-soluble chitosan did not induce any abnonnal changes. There were no abnormal findings due to the administration of the test substance in gross and microscopic findings. We had not found alteration in absolute and relative organ weight between the control and treated groups, with only exception in the liver but lacking dose-dependency. The results of hematology and serum biochemistry examination revealed that no treatment related changes were between control and all dose groups. In conclusion, it was suggested that subacute toxicity of the water-soluble chitosan was low and the no-observed adverse effect level was considered to be over 2,000 mg/kg in rats.

• The Journal of Internal Korean Medicine
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• v.21 no.5
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• pp.819-827
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• 2000

Purpose : To investigate the inhibitory effect of HCE on platelet aggragation and erythrocyte deformiability, we performed following experiments. Methods : Concentrated Hyulbuchukotang (HCE) was fed to rats for 10days. We compare normal group with $500{\beta}{\Sigma}/{\beta}{\Sigma}$-high dose group and $100{\beta}{\Sigma}/{\beta}{\Pi}$-low dose group. Results : HCE enhanced the blood filtration rate, erythrocyte deformiability, reduced the platelet aggreablilty and inhibited granule release from collagen stimulated platelet, the prostaglandin synthesis in platelat. Conclusion : HCE should inhibit thrombos formation due to platelet hyperaggraeability and reduction of erythrocyte defonmiability.

• The Journal of Internal Korean Medicine
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• v.21 no.5
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• pp.829-837
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• 2000

Purpose : To investigate the inhibitory effect of BHE on platelet aggregation and erythrocyte deformability, we performed following experiments. Methods : Concentrated Boyanghwanotang (BHE) was fed to rats for 10days. High dose group was treated with $500{\beta}{\partial}/kg$ and low dose group with $500{\beta}{\partial}/kg$. Results : BHE enhanced the blood filtration rate, reduced the platelet aggregability, inhibited granule release from collagen-stimulated platelet, the prostaglandin syn-thesis in platelet and enhanced erythrocyte deformability. Conclusion : BHE should inhibit thrombos formation due to platlete hyperaggregabili-ty and reduction of erythrocyte deformabi-lity.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1141-1146
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• 2010

Isolated the heterotrophic aerobic bacteria in sandfiltered water on NA and TSBA solid medium, selected 8 dominant species and identified by Sherlock System. Each samples are irradiated 0, 5, 16, 40 and $60\;mJ/cm^2$ using on CBD (Collimated Beam Device) Medium Pressure UV lamp after these identified bacterium did liquid culture how to make $10^6{\sim}10^7\;cells/mL$ suspended in dilution water. Then cultured bacteria are estimated inactivation rate on plate media. Identified Gram positive group are Bacillus Subtilus, Bacillus megaterium, Rhodococcus erythropolis and Microbacterium laevaniformans; Gram negative group are Pseudomonas vesicularis, Pseudomonas pseudoflava, Alcaligenes paradoxus and Zooglea ramigera. These isolation of bacterium are more stronger reference strain and high resistance of MP UV irradiation, Besides Gram negative bacterium are more sensitive Gram positive bacterium on MP UV dose. Now we are estimating to $60{\sim}100\;mJ/cm^2$ MP UV dose for efficient disinfection in water treatment plant.