• Asian-Australasian Journal of Animal Sciences
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• v.12 no.7
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• pp.1096-1103
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• 1999

A study was conducted to clarify the impact of recombinant porcine somatotropin (pST) on the efficiency of absorbed nitrogen use for protein deposition in growing pigs. Three levels of dietary crude protein (9.0, 11.5, 14.0% CP) were used. Each had either a sub-optimum or near optimum lysine: CP concentration (Low-lysine, 3.8 g/100 g CP and High-lysine, 5.5 g/100g CP) in order to achieve different metabolic efficiencies for nitrogen deposition (ca. 45 vs. 60%). Twelve crossbred female pigs $(59{\pm}4kg\;BW)$ were placed in metabolism cages and fitted with bladder catheters. Each pig received an excipient injection daily for the first 10-d, a pST (5 mg/d) injection for the second 10-d, and then excipient for the last 10-d. Pigs were randomly assigned to one of six dietary treatments (2 pigs/diet) and fed 4 times per d at $92g/kg\;BW^{0.75}$ $(3{\times}maintenance)$. Means for the excipient period were compared to means for the pST period. Urinary nitrogen (N) output declined in pST-treated pigs (p<0.01) irrespective of dietary protein content or lysine level. Nitrogen retention increased by an average of 11% (p<0.01) with pST treatment (726 vs. $803mg\;N/kg^{0.75}\;BW/d$). Forty-eight percent of the absorbed N was retained with Low-lysine diets, but this increased to 53% with pST injection (+11%, p<0.01). Pigs fed High-lysine diets retained 62% of absorbed N which increased to 69% with pST (+11% p<0.01). the addition of lysine improved N use by 27% (High vs. Low, p<0.01), but the effect of lysine and pST was additive (+40%). Therefore, pST improves N retention and the efficiency of apparently absorbed N use in growing pigs (>60kg). It does so with diets having the potential for either low or high efficiencies of N use (48% and 62%). More work is needed to determine if the partial efficiency of N use improves in direct proportion to pST dose since the improvement in protein deposition is a function of pST dose.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.20 no.2
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• pp.253-264
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• 1990

The purpose of this study was to estimate the distribution of absorbed doses of each important organs of head and neck region in panoramic radiography. Radiation dosimetry at internal anatomic sites and skin surfaces of phantom (RT-210 Humanoid Head & Neck Section/sup R/) was performed with lithium fluoride (TLD-100/sup R/) thermoluminescent dosimeters according to change of kilovoltage (65kVp, 75kVp and 85kVp) with 4 miliamperage and 20 second exposure time. The results obtained were as follows; Radiation absorbed doses of internal anatomic sites were presented the highest doses of 1.04 mGy, 1.065 mGy and 2.09 mGy in nasopharynx, relatively high doses of 0.525 mGy, 0.59 mGy and 1.108 mGy in deep lobe of parotid gland, 0.481 mGy, 0.68 mGy and 1.191 mGy in submandibular gland. But there were comparatively low doses of 0.172 mGy and 0.128 mGy in eyes and thyroid gland that absorbed dose was estimated at 85kVp. Radiation absorbed doses of skin surfaces were presented the highest doses of 1. 263 mGy, 1.538 mGy and 2.952 mGy in back side of first cervical vertebra and relatively high doses of 0.267 mGy, 0.401 mGy and 0.481 mGy in parotid gland. But there were comparatively low doses of 0.057 mGy, 0.068 mGy and 0.081 mGy in philtrum and 0.059 mGy in middle portion of chin that absorbed dose was estimated at 85kVp. According to increase of kilovoltage, the radiation absorbed doses were increased 1.1 times when kilovolt age changes from 65kVp to 75kVp and 1.9 times when kilovolt age changes from 75kVp to 85kVp at internal anatomic sites. According to increase of kilovoltage, the radiation absorbed doses were increased 1.3 times when kilovolt age changes from 65kVp to 75kVp and 1.6 times when kilovoltage changes from 75kVp to 85kVp at skin surfaces.

• Journal of Pharmaceutical Investigation
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• v.35 no.5
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• pp.349-353
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• 2005

This study reports the pharmacokinetics of a novel histone deacetylase inhibitor, SD-0542, in rats after i..v. and oral administration. SD-0542 was injected intravenously at doses of 10, 20, and 40 mg/kg. The terminal elimination half-life $(t_{1/2})$, systemic clearance (Cl), and steady-state volume of distribution $(V_{ss})$ remained unaltered as a function of dose, with their values ranging from 2.0-2.5 hr, 157.2-214.1 ml/min/kg, and 11.1-17.5 L/kg, respectively, whereas, the initial serum concentration $(C_0)$ and AUC increased linearly as the dose was increased. Renal excretion of SD-0542 was minimal. Oral pharmacokinetic studies were conducted in rats at a dose of 20 mg/kg. The $T_{max}$, Cl/F, $V_{z}/F$, and $t_{1/2}$ were 2.0 hr, 92864 ml/min/kg, 16331 L/kg, and 2.0 hr, respectively. Taken together, SD-0542 showed linear pharmacokinetics over the i.v. bolus dose range studied. SD-0542 was poorly absorbed, with the absolute oral bioavailability of 0.9%.

• Korean Journal of Digital Imaging in Medicine
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• v.13 no.2
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• pp.71-76
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• 2011

Because interventional procedure operates looking at premier as real time when perate intervention enemy, by patient is revealed during suitableness time in radiation, side effect such as radiation injury of skin is apt to happen. It established by purpose of study that measure exposure dose that patient receives about these problem, and find solution for radiation injury and repletion method. In this study, we used Rando phantom of identical structure with the human body which becomes accomplished with 4 branch ingredient of the attempt and system equivalent material them and absorbed dose were measured by TLD. According to the laboratory, it shows that operations such as TFCA procedure or uterine myoma embolization are more dangerous than TACE procedure. If both operations are inspected during a short time, it is not affected in being bombed. However, it can lead to palliative agenesis or depilate, definitive agenesis only if operations are repeated more than three times. Dose distibution based on experiment, to reduce radiation exposure to patients result from reduction of scatter ray as we control field size of radiation and protection of side organs except for tumor. also we knew that we can protect patients form radiation exposure, if we increas SOD and decrease SID.

• Progress in Medical Physics
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• v.15 no.4
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• pp.210-214
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• 2004

Since production of radioactive isotope for using PET, a lot of neutrons were produced. The produced neutrons were mainly shielded by concrete facility. Secondary photons are generated and emitted from the concrete shielding wall of the PET cyclotron since the proton-generated neutrons are thermalized and absorbed in the concrete wall and emit secondary radiations, i.e., photons. This study calculated neutron dose and photon dose at outside of the accelerator facility using MCNPX code. As results of the calculation, total dose were calculated less than limited dose by law.

• Nuclear Engineering and Technology
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• v.44 no.5
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• pp.483-490
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• 2012

PWR spent fuels produced in the Republic of Korea are expected to be recycled by pyroprocess in the long term future. Even though pyroprocess waste amounts can be smaller than that of PWR spent fuel assembly in case of direct disposal, this process essentially will produce various and unique radioactive wastes. The goals of this article are to characterize these wastes, calculate the amount of wastes, design disposal systems for each waste and evaluate the radiation safety of each system by dose assessment. The absorbed dose results of the metal and ceramic waste for the engineering barrier system (EBS) showed $2.21{\times}10^{-2}$ Gy/h and $1.15{\times}10^{-2}$ Gy/h, which are lower than the recommended value of 1 Gy/h. These results confirmed that the newly proposed disposal systems have a safety margin for the radiation produced from each waste.

• Journal of radiological science and technology
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• v.45 no.5
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• pp.433-438
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• 2022

Targeted radionuclides treatment (TRT) requires the establishment of treatment plans that consider various factors, such as the type of radionuclides, target organs, and administration methods. For this reason, in this study, the absorption dose of a single cell was analyzed according to the type of radioisotope used to treat target radionuclides. In this study, a simulation was performed on beta rays used in the treatment of target radionuclides at the cell level using MCNPX (ver. 2.5.0). First, according to the calculation formula, the beam path according to the type of radioisotope for treatment was calculated. Second, the amount of self-radiation by beta rays emitted from cell diameters of 5 ㎛ and 10 ㎛ cell nuclei was evaluated. As a result, it showed a high range proportional to the maximum energy of the beta-ray, and the highest self-dose distribution from 177 Lu radiation sources among therapeutic radioisotopes. This was analyzed as a result that is inversely proportional to the maximum energy of the beta-ray, and it suggests that the selection of a nuclide considering the range of the beta-ray is necessary in the treatment of target radionuclides in the future.

• Progress in Medical Physics
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• v.24 no.4
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• pp.253-258
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• 2013

The purpose of this study is to evaluate and analyze the relationship between the external radiation dose reconstruction which is transmitted from the patient who receives radiation treatment through electronic portal imaging device (EPID) and the internal dose derived from the Monte Carlo simulation. As a comparative analysis of the two cases, it is performed to provide a basic indicator for similar studies. The geometric information of the experiment and that of the radiation source were entered into Monte Carlo n-particle (MCNPX) which is the computer simulation tool and to derive the EPID images, a tally card in MCNPX was used for visualizing and the imaging of the dose information. We set to source to surface distance (SSD) 100 cm for internal measurement and EPID. And the water phantom was set to be 100 cm of the source to surface distance (SSD) for the internal measurement and EPID was set to 90 cm of SSD which is 10 cm below. The internal dose was collected from the water phantom by using mesh tally function in MCNPX, accumulated dose data was acquired by four-portal beam exposures. At the same time, after getting the dose which had been passed through water phantom, dose reconstruction was performed using back-projection method. In order to analyze about two cases, we compared the penetrated dose by calibration of itself with the absorbed one. We also evaluated the reconstructed dose using EPID and partially accumulated (overlapped) dose in water phantom by four-portal beam exposures. The sum dose data of two cases were calculated as each 3.4580 MeV/g (absorbed dose in water) and 3.4354 MeV/g (EPID reconstruction). The result of sum dose match from two cases shows good agreement with 0.6536% dose error.

• The Korean Journal of Nuclear Medicine Technology
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• v.14 no.2
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• pp.41-44
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• 2010

Purpose: Along with recent advances in PET/CT instrumentation and imaging technology, the number of patients has also been steadily increasing. This resulted in the increased radiation exposure to radiation workers in PET/CT rooms. In this study, we installed a radiation shield and investigated whether it could reduce radiation exposure to the workers and thus enhance job satisfaction. Materials and Methods: A radiation shield is composed of 5 cm thick lead and has a structure in which a radiation worker sits and watches a patient through lead glass while injecting radiopharmaceutical to the patient. Quarterly absorbed dose of radiation workers was measured using thermoluminescence dosimeters (TLD) and the results were compared for six months each before and after installation of the radiation shield. Exposure dose was also measured using a pocket dosimeter placed at the same location in the front and the back of the radiation shield. In addition, frequency of use of the shield and job satisfaction of radiation workers were investigated using a survey. Results: Quarterly absorbed dose of radiation workers was 2.70 mSv on average before installation of new radiation shield, whereas that dropped to 2.13 mSv after installation of radiation shield, reducing radiation exposure dose by 21%. Exposure dose on the front side of the shield was 61.2 R, whereas that on the back side of shield was 2.8 R. According to the survey, 85% of workers used the shield and were satisfied with the outcome: each radiation worker made injections to patients average of 6.5 times/day and preferred sitting to standing while injecting radiopharmaceutical to patients. Conclusion: Use of radiation shield reduced the exposure dose of radiation workers, which is the ultimate goal of radiation protection to minimize radiation exposure and is an appropriate method for the improvement of hospital working environment. Furthermore, we found that use of radiation shield not only relieves physical and psychological burden of radiation workers but also enhances job satisfaction. This result indicates that use of radiation shield is important for improvement of the radiation workers' job environment in terms of radiation protection.

• Progress in Medical Physics
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• v.11 no.2
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• pp.147-155
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• 2000

Patient dose verification is one of the most important parts in quality assurance of the treatment delivery for radiation therapy. The dose distributions may be meaningfully improved by modulating two dimensional intensity profile of the individual high energy radiation beams In this study, a new method is presented for the pre-treatment dosimetric verification of these two dimensional distributions of beam intensity by means of a charge coupled device video camera-based fluoroscopic device (henceforth called as CCD-VCFD) as a radiation detecter with a custom-made software for dose calculation from fluorescence signals. This system of dosimeter (CCD-VCFD) could reproduce three dimensional (3D) relative dose distribution from the digitized fluoroscopic signals for small (1.0$\times$1.0 cm$^2$ square, ø 1.0 cm circular ) and large (30$\times$30cm$^2$) field sizes used in intensity modulated radiation therapy (IMRT). For the small beam sizes of photon and electron, the calculations are performed In absolute beam fluence profiles which are usually used for calculation of the patient dose distribution. The good linearity with respect to the absorbed dose, independence of dose rate, and three dimensional profiles of small beams using the CCD-VCFD were demonstrated by relative measurements in high energy Photon (15 MV) and electron (9 MeV) beams. These measurements of beam profiles with CCD-VCFD show good agreement with those with other dosimeters such as utramicro-cylindrical (UC) ionization chamber and radiographic film. The study of the radiation dosimetric technique using CCD-VCFD may provide a fast and accurate pre-treatment verification tool for the small beam used in stereotactic radiosurgery (SRS) and can be used for verification of dose distribution from dynamic multi-leaf collimation system (DMLC).