• Journal of radiological science and technology
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• v.39 no.4
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• pp.577-585
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• 2016

The purpose of this study is to evaluate the accuracy of beam delivery QA software using the MLC dynalog file, about the VMAT plan with AAPM TG-119 protocol. The Clinac iX with a built-in 120 MLC was used to acquire the MLC dynalog file be imported in MobiusFx(MFX). To establish VMAT plan, Oncentra RTP system was used target and organ structures were contoured in Im'RT phantom. For evaluation of dose distribution was evaluated by using gamma index, and the point dose was evaluated by using the CC13 ion chamber in Im'RT phantom. For the evaluation of point dose, the mean of relative error between measured and calculated value was $1.41{\pm}0.92%$(Target) and $0.89{\pm}0.86%$(OAR), the confidence limit were 3.21(96.79%, Target) and 2.58(97.42%, OAR). For the evaluation of dose distribution, in case of $Delta^{4PT}$, the average percentage of passing rate were $99.78{\pm}0.2%$(3%/3 mm), $96.86{\pm}1.76%$(2%/2 mm). In case of MFX, the average percentage of passing rate were $99.90{\pm}0.14%$(3%/3 mm), $97.98{\pm}1.97%$(2%/2 mm), the confidence limits(CL) were in case of $Delta^{4PT}$ 0.62(99.38%, 3%/3 mm), 6.6(93.4%, 2%/2 mm), in case of MFX, 0.38(99.62%, 3%/3 mm), 5.88(94.12%, 2%/2 mm). In this study, we performed VMAT QA method using dynamic MLC log file compare to binary diode array chamber. All analyzed results were satisfied with acceptance criteria based on TG-119 protocol.

• International Journal of Highway Engineering
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• v.10 no.4
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• pp.103-116
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• 2008

In this study, in-situ testing method, Dynamic Cone Penetration Test(DCPT) was presented to establish a new compaction control criteria with using mechanical property like elastic modulus instead of unit weight for field compaction control. Soil chamber tests and in-situ tests were carried out to confirm DCPT tests can predict the designed elastic modulus after field compaction, and correlation analysis among the DCPT, CBR and resilient modulus of sub grade were performed. Also, DCPT test spacing criteria in the construction site was proposed from the literature review. In the result of laboratory tests, Livneh's equation was the best in correlation between PR of DCPT and CBR, George and Pradesh's equation was the best in the predicted resilient modulus. In the resilient modulus using FWD, Gudishala's equation estimates little larger than predicted resilient modulus and Chen's equation estimates little smaller. And KICT's equation estimates the modulus smaller than predicted resilient modulus. But using the results of laboratory resilient modulus tests considering the deviatoric and confining stress from the moving vehicle, the KICT's equation was the best. In the results of In-situ DCPT tests, the variation of PR can occur according to size distribution of penetrate points. So DCPT test spacing was proposed to reduce the difference of PR. Also it was shows that average PR was different according to subgrade materials although the subgrade was satisfied the degree of compaction. Especially large sized materials show smaller PR, and it is also found that field water contents have influence a lot of degree of compaction but a little on the average PR of the DCPT tests.

• Korean Journal of Agricultural and Forest Meteorology
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• v.11 no.2
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• pp.52-60
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• 2009

This study was conducted to quantify the soil respiratory $CO_2$ emission (SR) in an apple orchard and to determine its relationship with key environmental factors such as air temperature, soil temperature and soil moisture content. Experiment was made over the period from 23 April 2007 to 31 March 2008 in 'Fuji' apple orchard of National Institute of Horticultural and Herbal Science in Suwon, Gyeonggi-do, Korea. The SR was measured by using the automatic opening/closing chamber system based on a closed method. Diurnal variations in SR showed an increase around 0700 hours with increasing soil temperature, its peak between 1400 and 1500 hours, and then a gradual decrease thereafter. Daily variations in SR depended largely on soil and air temperatures over the year, ranging from 0.8 to 13.7 g $CO_2$ $m^{-2}d^{-1}$. During the rainy spell in summer (July$\sim$Autumn) with higher temperature and more precipitation, the SR was lower than that in the spring (May$\sim$June) with moderate temperature. The SR showed a significant exponential relationship with soil temperature ($r^2=0.800$) and air temperature ($r^2=0.805$), but not with soil moisture content ($r^2=0.160$). The $Q_{10}$ values of SR with annual soil temperature and air temperature were 2.0 and 1.9, respectively. The annually integrated SR was 19.6 ton $CO_2$ $ha^{-1}$.

• Tuberculosis and Respiratory Diseases
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• v.49 no.2
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• pp.189-197
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• 2000

Background : Tissue inhibitor of metalloproteinase is a natural inhibitor that counteracts pro teolytic enzymes essential to the invasion of cancer cell. Whether or not TIMP-2 gene transfer via adenovirus could inhibit the invasion of lung cancer cell iη vitro was evaluated for the future purpose of gene therapy against lung cancer. Methods : Recombinant adenovirus-TIMP-2(Ad-TIMP-2) was generated by homologous recombination after pACCMV-TIMP-2 and pJM17 were cotransfected into 293 cell by standard calcium phosphate coprecipitate method. Calu-6, one of the most invasive lung cancer cells, was transduced with Ad-TIMP-2 or Ad-$\beta$gal. Anchorage-independent growth and invasiveness were assessed by soft agar clonogenicity assay and invasion assay using two-chamber, well divided by matrigel. Results : Ad-TIMP-2 transduced calu-6 cells produced biologically active TIMP-2 more than 50 times more than parental calu-6. TIMP-2 gene transfer did not suppress the in vitro tumorigenicity. However, two chamber well assay revealed that Ad-TIMP-2 transduction reduced the invasiveness of calu-6 efficiently (12% compared with parental cell) even at low 10moi. Conclusion : Even though TIMP-2 gene transfer did not inhibit in vitro tumorigenicity, it did inhibit invasion of lung cancer cell in vitro. The inhibition of invasion by Ad-TIMP-2 may be a useful strategy for the treatment of lung cancer.

• Journal of the Korean Society of Radiology
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• v.15 no.7
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• pp.965-973
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• 2021

Since radiation therapy is irradiated with high-energy X-rays in a variety of at least 20 Gy to 80 Gy, a high dose is administered to the local area where the tumor is located, and various side effects of some normal tissues are expected. Currently, in clinical practice, lead, a representative material, is used as an effort to shield normal tissues, but lead is classified as a heavy metal harmful to the human body, and a large amount of skin contact can cause poisoning. Therefore, this study intends to manufacture a measurement sheet that can compensate for the limitations of lead using the materials Tungsten, Brass, and Copper of the 3D printer of the FDM (Fused Deposition Modeling) method and to investigate the penetration performance. Tungsten mixed filament transmission measurement sheet size was 70 × 70 mm and thickness 1, 2, 4 mm using a 3D printer, and a linear accelerator (TrueBeam STx, S/N: 1187) was measured by irradiating 100 MU at SSD 100 cm and 5 cm in water using a water phantom, an ion chamber (FC-65G), and an elcetrometer (PTW UNIDOSE), and the permeability was evaluated. As a result of increasing the measurement sheet of each material by 1 mm, in the case of Tungsten sheet at 3.8 to 3.9 cm in 6 MV, the thickness of the lead shielding body was thinner than 6.5 cm, and in case of Tungsten sheet at 4.5 to 4.6 cm in 15 MV. The sheet was thinner than the existing lead shielding body thickness of 7 cm, and equivalent performance was confirmed. Through this study, the transmittance measurement sheet produced using Tungsten alloy filaments confirmed the possibility of transmission shielding in the high energy region. It has been confirmed that the usability as a substitute is also excellent. It is thought that it can be provided as basic data for the production of shielding agents with 3D printing technology in the future.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.28 no.3
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• pp.223-229
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• 2022

This study was conducted to investigate the effect of packaging methods and sterilization treatment on storability and microbial control in paprika fruits. When treated with chlorine dioxide gas for 3, 6, and 12 hours and cold plasma gas for 1, 3, and 6 hours, and then packed in a carton box and stored in a 8 ± 1℃ chamber for 7 days, chlorine dioxide treated 12 hours and plasma treated 6 hours was prevented the development of E·coli and YM(yeast and mold). Accordingly, the control was treated with chlorine dioxide for 12 hours and plasma for 6 hours, packed using a carton box and 40,000 cc·m^-2·day^-1·atm^-1 OTR film (MAP), and stored in a 8 ± 1℃ chamber for 20 days. Fresh weight loss rate during storage was less than 1% in the MAP treatments, and the visual quality of the MAP treatments was above the marketability limit until the end of storage. There was no difference in the contents of oxygen, carbon dioxide, and ethylene in the film. In the case of firmness, the chlorine dioxide treatments was low, and the Hunter a^* value, which showed chromaticity, was highest in the Plasma 6h MAP treatment. Off-odor was investigated in the MAP treatments, but it was very low. The rate of mold growth on the fruit stalk of paprika was the fastest and highest in the chlorine dioxide treated box packaging treatments, and the lowest in the chlorine dioxide treated MAP treatments at the end of storage. The aerobic count in the pulp on the storage end date was the lowest in the plasma treated box packaging treatments, the lowest number of E·coli in the chlorine dioxide treated MAP treatments, and the lowest yeast & mold in the chlorine dioxide treated box packaging treatments. As a result, for the inhibition of microorganisms during paprika storage, it is considered appropriate to treat plasma for 6 hours before storage regardless of the packaging method.

• Journal of the Korean Society of Radiology
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• v.18 no.3
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• pp.257-265
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• 2024

In this study, we applied AEC(Auto Exposure Control), which is used in many chest examinations, to evaluate whether medical devices inserted into the body affect the dose and image quality of chest images. After attaching three HIMD(Human implantable medical devices) to the ion chamber, the Monte Carlo methodology-based program PCXMC(PC Program for X-ray Monte Carlo) 2.0 was applied to measure the effective dose by inputting the DAP(Dose Ares Product) value derived from the Pacemaker and CRT and Chemoport Additionally, to evaluate image quality, we set three regions of interest and one noise region on the chest and measured SNR and CNR. The final study results showed significant differences in DAP and Effective dose. There was a significant difference between Pacemaker and CRT when AEC was applied and not applied. (p<0.05) When applied, the dose increased by 37% for Pacemaekr and 52% for CRT. Chemoport showed a 10% increase in effective dose depending on whether AEC was applied, but there was no significant difference. (p>0.05) In the image quality evaluation, there was no significant difference in image quality between all HIMD insertions and AEC applied or not. (p>0.05) Therefore, when the HIMD was inserted into the chest during a chest x ray and overlapped with the ion chamber sensor, the effective dose increased, and there was no difference in image quality even at a low dose without AEC. Therefore, when performing a chest X-ray examination of a patient with a HIMD inserted, it is considered that performing the examination without applying AEC is a method that can be considered to reduce the patient's radiation exposure.

• Journal of radiological science and technology
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• v.26 no.2
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• pp.37-42
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• 2003

Purpose : Computed tomographic equipment is essential for diagnosis by means of radiation. With passage of time and development of science computed tomographic was developed time and again and in future examination by means of this equipment is expected to increase. In this connection these authors measured rate of scatter ray generation at front of lead glass for patients within control room of computed tomographic equipment room and outside of entrance door for exit and entrance of patients and attempted to ind out method for minimizing exposure to scatter ray. Material and Method : From November 2001 twenty five units of computed tomographic equipments which were already installed and operation by 13 general hospitals and university hospitals in Seoul were subjected to this study. As condition of photographing those recommended by manufacturer for measuring exposure to sauter ray was use. At the time objects used DALI CT Radiation Dose Test Phantom fot Head (${\oint}16\;cm$ Plexglas) and Phantom for Stomache(${\oint}32\;cm$ Plexglas) were used. For measurement of scatter ray Reader (Radiation Monitor Controller Model 2026) and G-M Survey were used to Survey Meter of Radical Corporation, model $20{\times}5-1800$, Electrometer/Ion Chamber, S/N 21740. Spots for measurement of scatter ray included front of lead glass for patients within control room of computed tomographic equipment room which is place where most of work by gradiographic personnel are carried out and is outside of entrance door for exit and entrance of patients and their guardians and at spot 100 cm off from isocenter at the time of scanning the object. The results : Work environment within computed tomography room which was installed and under operation by each hospital showed considerable difference depending on circumstances of pertinent hospitals and status of scatter ray was as follows. 1) From isocenter of computed tomographic equipment to lead glass for patients within control room average distance was 377 cm. At that time scatter ray showed diverse distribution from spot where no presence was detected to spot where about 100 mR/week was detected. But it met requirement of weekly tolerance $2.58{\times}10^{-5}\;C/kg$(100 mR/week). 2) From isocenter of computed tomographic equipment to outside of entrance door where patients and their guardians exit and enter was 439 cm in average, At that time scatter ray showed diverse distribution from spot where almost no presence was detected to spot with different level but in most of cases it satisfied requirement of weekly tolerance of $2.58{\times}10^{-6}\;C/kg$(100 mR/week). 3) At the time of scanning object amount of scatter ray at spot with 100 cm distance from isocenter showed considerable difference depending on equipments. Conclusion : Use of computed tomographic equipment as one for generation of radiation for diagnosis is increasing daily. Compared to other general X-ray photographing field of diagnosis is very high but there is a high possibility of exposure to radiation and scatter ray. To be free from scatter ray at computed tomographic equipment room even by slight degree it is essential to secure sufficient space and more effort should be exerted for development of variety of skills to enable maximum photographic image at minimum cost.

• Tuberculosis and Respiratory Diseases
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• v.53 no.4
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• pp.409-419
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• 2002

Background : The therapeutic effects of surfactant on acute lung injury derive not only from its recruiting action on collapsed alveoli but also from its anti-inflammatory effects. Pro-apoptotic action on alveolar neutrophils represents one of the important anti-inflammatory mechanisms of surfactant. In the present study, we evaluated the effects of sufactant on the apoptosis of human peripheral and rat alveolar neutrophils. Methods : In the (Ed- the article is not definitely needed but it helps to separate the two prepositions 'in') in vitro study, human neutrophils were collected from healthy volunteers. An equal number of neutrophils ($1{\times}10^6$) (Ed-confirm) was treated with LPS (10, 100, 1000ng/ml), surfactant (10, 100, $1000{\mu}g/ml$), or a combination of LPS (1000ng/ml) and surfactant (10, 100, $1000{\mu}g/ml$). After incubation for 24 hours, the apoptosis of neutrophils was evaluated by Annexin V method. In the in vivo study, induction of acute lung injury in SD rats by intra-tracheal instillation of LPS (5mg/kg) was followed by intra-tracheal administration of either surfactant (30mg/kg) or normal saline (5ml/kg). Tenty-four hours after LPS instillation, alveolar neutrophils were collected and the apoptotic rate was evaluated by Annexin V method. In addition, changes of the respiratory mechanics of rats (respiratory rate, tidal volume, and airway resistance) were evaluated with one chamber body plethysmography before, and 23 hours after, LPS instillation. Results : in the in vitro study, LPS treatment decreased the apoptosis of human peripheral blood neutrophils (control: $47.4{\pm}5.0%$, LPS 10ng/ml; $30.6{\pm}10.8%$, LPS 100ng/ml; $27.5{\pm}9.5%$, LPS 1000ng/ml; $24.4{\pm}7.7%$). The combination of low to moderate doses of surfactant with LPS promoted apoptosis (LPS 1000ng/ml + Surf $10{\mu}g/ml$; $36.6{\pm}11.3%$, LPS 1000ng/ml +Surf $100{\mu}g/ml$; $41.3{\pm}11.2%$). The high dose of surfactant ($1000{\mu}g/ml$) decreased apoptosis ($24.4{\pm}7.7%$) and augmented the anti-apoptotic effect of LPS (LPS 1000ng/ml + Surf $1000P{\mu}g/ml$; $19.8{\pm}5.4%$). In the in vivo study, the apoptotic rate of alveolar neutrophils of surfactant-treated rats was higher than that of normal saline-treated rats ($6.03{\pm}3.36%$ vs. $2.95{\pm}0.58%$). The airway resistance (represented by Penh) of surfactant-treated rats was lower than that of normal saline-treated rats at 23 hours after LPS injury ($2.64{\pm}0.69$ vs. $4.51{\pm}2.24$, p<0.05). Conclusion : Surfactant promotes the apoptosis of human peripheral blood and rat alveolar neutrophils. Pro-apoptotic action on neutrophils represents one of the important anti-inflammatory mechanisms of surfactant.

• The Journal of Korean Society for Radiation Therapy
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• v.30 no.1_2
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• pp.107-116
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• 2018

Purpose : Intensity-modulated radiation therapy(IMRT) has been widely used for radiation therapy of Prostate Cancer because it can reduce radiation adverse effects on normal tissues and deliver more dose to the Prostate than 3D radiation therapy. Volumetric modulated arc therapy(VMAT) has been widely used due to recent advances in equipment and treatment techniques. VMAT can reduce treatment time by up to 55 % compared to IMRT, minimizing motion error during treatment. Materials and Methods : In this study, compared the MU and DVH values of 10 patients with prostate cancer by classifying them into 4 groups with 5 LN-Prostate groups and 5 Only-Prostate. And DQA measurements were performed using ArcCHECK and MapCHECK. Results : The results of Target and OAR dose distribution of Prostate patients are as follows. $D_{max}$ was in the range of 100~110 % in 4 groups, and more than 110 % of hot spot was not seen. Only-Prostate ($P_1$, $P_2$) without LN had a satisfactory dose distribution for the target dose, but slightly better for 2 arc plan($P_2$) than 1 arc plan($P_1$). The target dose $D_{98%}$ distribution in the LN-Prostate ($P_{L1}$, $P_{L2}$) group showed better 2 arc plan($P_{L2}$) than 1 arc plan($P_{L1}$), But in the case of 1 arc plan($P_{L1}$), the target dose $D_{98%}$ value was not enough. In OAR, the dose distribution of 1 Arc($P_1$) Plan and 2 Arc($P_2$) Plan in the Only-Prostate ($P_1$, $P_2$) Group satisfied the prescribed dose value. But, The dose distribution of 1 arc($P_1$) was slightly higher. In LN-Prostate OAR, 1 Arc($P_{L1}$) Plan showed higher dose than the prescribed dose. The Gamma evaluation pass rate of ArcCHECK and MapCHECK calculated from the DQA measurements was slightly higher than 99 % and the mean error range of the point dose measurements using the CC04 ion chamber was less than 1 %. Conclusion : In this study, Only-Prostate ($P_1$, $P_2$) group, the dose of 2 Arc plan was better. However, considering the treatment time and MU value, 1 Arc treatment method was more suitable. In the LN-Prostate ($P_{L1}$, $P_{L2}$) group, 2 Arc($P_{L2}$) treatment method showed better results and satisfied with Target $D_{98%}$ and OAR prescription dose.