• Nuclear Engineering and Technology
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• 제55권5호
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• pp.1757-1762
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• 2023

Radiological hazards from external exposure of naturally occurring radioactive materials (NORM) scales residues, generated during the extraction process of oil and gas production in southern Algeria, are evaluated. The activity concentrations of ²²⁶Ra, ²³²Th, and ⁴⁰K were measured using high-purity gamma-ray spectrometry (GeHP). Mean activity concentration of ²²⁶Ra, ²³²Th and ⁴⁰K, found in scale samples are 4082 ± 41, 1060 ± 38 and 568 ± 36 Bq kg^-1, respectively. Radiological hazard parameters, such as radium equivalent (Ra_eq), external and internal hazard indices (H_ex, H_in), and gamma index (I_γ) are also evaluated. All hazard parameter values were greater than the permissible and recommended limits and the average annual effective dose value exceeded the dose constraint (0.3 mSv y^-1). However, for occasionally exposed workers, the dose rate of 0.65 ± 0.02 mSv y^-1 is lower than recommended limit of 1 mSv y^-1 for public.

• 화훼연구
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• 제19권2호
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• pp.119-125
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• 2011

창포는 한국에 자생하는 수생식물로 약용뿐만 아니라 phytoremediation과 수질정화 식물로도 알려져 있다. 본 연구에서는 창포의 기내 식물체에 다양한 선량(20-500 Gy)의 감마선을 조사하여, 방사선의 효과 및 감수성을 확인하기 위해 2달후 생존율, 신초형성율 및 생장율을 측정하였다. 생존율과 신초형성율은 감마선 선량이 증가할수록 현저하게 감소하였다. 기내에서 저선량을 조사한 식물체의 생장율은 대조구에 비해 오히려 증가하였으나, 250 Gy 이상에서는 생장이 멈추거나 유의하게 감소하였으며, 반치사선량($LD_{50}$)은 240 Gy로 다른 식물종의 $LD_{50}$보다 훨씬 높은 선량이었다. 창포에서 저선량을 조사하였을 때 생장율이 증가하는 방사선호메시스(radiation hormesis) 효과를 확인하였다.

• 방사선산업학회지
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• 제12권4호
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• pp.277-285
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• 2018

Patients administered radioisotope for medical purposes are regulated by each country to quarantine them until their body's radioactivity contents decrease below release criteria. To predict the quarantine period and provide it to medical staffs and patients, it is necessary to approach the assessment of the exposure dose of persons due to patients in a realistic manner. For this purpose, a whole-body effective half-life should be applied to the dose assessment equation instead of the physical half-life. In this study, we constructed a bio-kinetic model for each nuclear species based on the ICRP publication to obtain a whole-body effective half-life of 10 unsealed gamma-ray emitting nuclei from the notification of Nuclear Safety and Security Commission, and calculated the effective half-life mathematically by simulating the distribution of the radioisotope administered in the whole body as well as each organ scale. The whole-body effective half-life of $^{198}Au$, $^{67}Ga$, $^{123}I$, $^{111}In$, $^{186}Re$, $^{99m}Tc$, and $^{201}TI$ were 1,93, 2.57, 0.295, 2.805, 1.561, 0.245, and 2.397 days respectively. However, it was found to be undesirable to offer a single value of the effective half-life of $^{125}I$, $^{131}I$, and $^{169}Yb$ because the changes in the effective half-life show no linearity. A bio-kinetic model created for the internal exposure assessment has been shown to be possible to calculate the effective half-life of radioisotopes administered in the patient's body, but subsequent studies of radiolabeled compounds are required as well.

• 생명과학회지
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• 제24권11호
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• pp.1174-1179
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• 2014

본 연구는 감마선이 새로운 품종의 버섯을 개발하는데 이용 될 수 있는지 평가하기 위하여 수행하였다. 본 연구를 한국, 일본, 대만 등의 느티만가닥버섯 20종류, 한국 잿빛느티만가닥버섯 5종류, 일본 땅지만가닥버섯 등의 3품종과 돌연변이체의 유전적 변이를 분석하였다. 50~2,000 Gy의 감마선을 느티만가닥버섯 포자에 조사하였다. 포자를 이용한 돌연변이 유발의 감마선 적정선량은 50~500 Gy의 저준위선량이었다. 돌연변이 단핵균사를 교배하여 이핵균주를 만들었다. 돌연변이 균주와 재래종의 버섯들로부터 DNA를 추출하여 16S ribosomal DNA, ITS의 전부분 28S ribosomal DNA의 일부분이 포함된 ITS서열을 분석을 하였다. 분석한 ITS서열의 길이는 1,052~1,143 뉴클레오티드였다. Nei-Li's 방법에 의해 유전적 유연 관계계를 분석하였다. 느티만가닥버섯 품종들간의 비유사도는 0~3.5%였다. 또한 Neighbor-Joining (NJ)방법에 의해 계통수를 작성하였다. 그 결과 느티만가닥버섯의 품종간의 비유사도는 0~3.5%였다. 또한 23품종과 5 돌연변이 이 그룹의 ITS서열을 바탕으로 한 계통순는 12 cluster를 나타내었다. 돌연변이 균주들은 서로 다른 cluster를 형성하였다. 무작위적인 돌연변이가 발생하였음을 알 수 있었다. 이상의 연구결과들을 감마선이 버섯의 품종개량을 위한 수단이 될 수 있음을 보여주었다.

• 동아시아식생활학회지
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• 제8권4호
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• pp.412-421
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• 1998

보리, 옥수수, 대두, 팥 등에 1.2, 10.1, 30.5 kGy의 감마선 조사처리를 하였을 때 조사선량에 따른 잡곡류의 물리화학적, 미생물적 특성의 변화를 조사하였다. 시료의 수분함량과 조지방함량은 감마선 조사에 의해 유의적인 차이를 보이지 않았고, TBA가는 30.5 kGy로 조사한 보리와 옥수수에서 증가하였다. 미생물 검사에서 보리, 옥수수, 대두, 팥의 중온성균과 저온성균은 감마선 조사에 의해 그 수가 감소하였으며 초기오염도가 낮은 효모 및 곰팡이는 1.2 kGy의 저선량 조사로도 검출한계 이하로 사멸이 가능하였다. 옥수수를 제외한 잡곡류의 환원당은 감마선 조사에 의해 유의적으로 변하지 않았고 대두의 stachyose, raffinose, sucrose와 보리의 sucrose함량은 30.5 kGy 조사시 증가하였다. Riboflavin은 30.5 kGy로 조사한 팥을 제외하고는 감마선 조사에 의해 감소하지 않았다. 색도에서는 감마선 조사에 의해 팥분말의 b값이 증가하였고, 대두분 말의 L값은 감소하였다. 30.5 kGy로 조사한 보리분말의 L값, a값, b값은 약간 증가하였고, 옥수수 분말의 b값은 10.1 kGy와 30.5 kGy조사시 감소하였다.

• 한국가금학회지
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• 제24권3호
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• pp.107-116
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• 1997

In order to achieve optimal reproductive performance, reliable morphological and physiological basic data on the reproductive organs are desirable. Adult male Korean ring-necked pheasant in inactive(mid of January) and active state (end of April) were used in this study. In addition, five active state pheasants were received a single dose of 60Co-ray 500 rads each to damage the testes. The objective of this study was to investigate the distribution pattern of protein gene product (PGP) 9.5 and ${\alpha}$-tubulin in the pheasant testes of the active, inactive and ${\gamma}$-ray irradiated active states. The results obtained were summarized as follows 1. The seminiferous tubules collected in inactive states( mid of Jan) showed narrow lumen, and the spermatogonia and the Sertoli cell were well preserved. The PGP 9.5 immunoreactivity of these tubules showed a positive reaction in paranucleus area of the spermatogonia, and a positive reaction in a small number of the Leydig cells in the interstitium of the seminiferous tubules. 2. The seminiferous tubules were dilated in active state(end of April) as compared with the inactive state. The PGP 9.5 reactivity in these tubules showed a positive reaction in many Leydig cells in the interstitium of the seminiferous tubules, and the testes of ${\gamma}$-ray irradiated group showed partially weak reaction in the interstitium of the seminiferous tubules. 3. The ${\alpha}$-tubulin reactivity in the seminiferous tubules of the inactive testes was strongly positive in the cytoplasmic process of the Sertoli cell from the basal stem region to the apical ex-tension. From the broad part of the stem region to the luminal space, the active testes showed a strong positive reaction. The ${\gamma}$-ray irradiated groups showed diminished reaction in the basal region.

• 한국식품저장유통학회지
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• 제8권1호
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• pp.9-15
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• 2001

밤(Castanea crenata, 은기)의 저장특성에 대하여 수침처리와 감마선 조사의 영향을 검토하기 위하여, 수확된 밤을 48시간 동안 수침 처리한 후 0, 0.15, 0.25 및 0.35 kGy의 감마선을 조사하고 $0^{\circ}C$와 95$\pm$2%의 상대습도에서 9개월 동안 저장하면서 품질변화를 측정하였다. 발아현상은 수침 처리된 밤에서만 저장말기에 나타났으며, 감마선을 0.35 kGy 조사한 밤에서는 발아되지 않았다. 수침처리 밤에서는 조사 선량에 무관하게 저장 초반기부터 부패가 발생되어 수침처리 되지 않은 경우보다 저장 9개월 후 약 2배의 부패율을 보였다. 중량감소는 수침 처리된 밤이 무처리 밤보다 적었으며, 조사선량의 영향은 없었다. 과육경도는 수침처리를 하지 않은 경우 감마선 조사에 의해 감소가 억제되었으며, 고선량 일수록 높게 유지되는 경향이었다. 전당함량은 감마선이 조사된 밤이 조사되지 않은 밤보다 저장말기에 높게 유지되었으며 선량에 따른 차이는 없었다. 비타민 C 함량은 감마선 조사 직후 다소 감소되었으나 저장 중 변화는 감마선 조사된 밤에서 완만하게 감소되었다. 가용성 탄닌의 함량은 발아억제 선량 범위의 감마선 조사에 영향을 받지 않았다.

• Advances in materials Research
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• 제3권4호
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• pp.183-197
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• 2014

Copolymers of gelatin and poly (vinyl alcohol), (PVA) grafted by acrylic acid (AAc) with excellent water absorption and retention abilities under neutral conditions were successfully synthesized using $^{60}Co$ gamma radiations in presence of ammonium persulphate (APS), as water soluble initiator and sodium bicarbonate ($NaHCO_3$) as foaming agent. The optimum synthesis conditions pertaining to maximum swelling percentage were evaluated as a function of gelatin/PVA ratio, amount of water, concentration of APS, $NaHCO_3$, monomer concentration and total irradiation dose. Maximum percent swelling (1694.59%) of the copolymer, gelatin-co-PVA, was obtained at optimum $[APS]=2.92{\times}10^{-1}mol/L$, $[NaHCO_3]=7.94{\times}10^{-2}mol/L$ and 1.5 mL of water at total dose of 31.104 kGy while in case of grafted copolymer, (gelatin-co-PVA)-g-poly(AAc), maximum percent swelling (560.86%) was obtained using $8.014{\times}10^{-1}mol/L$ of AAc in 9 mL water with 31.104 kGy preirradiation dose. The pristine and grafted copolymers were characterized by Fourier Transform Infrared Spectroscopy (FTIR), Scanning electron Microscopy (SEM), Thermal gravimetric analysis (TGA) and X-Ray Diffraction (XRD) methods. The copolymers loaded with an antiseptic, Povidone, were used as wound dressing materials for wounded gastrocnemius muscle of mice and the results exhibit that (gelatin-co-PVA)-g-poly (AAc) copolymer is a potent wound dressing material as compared to the copolymer.

• 한국의학물리학회지:의학물리
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• 제27권3호
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• pp.169-174
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• 2016

The aim of this study is to investigate the delivery accuracy of intensity-modulated radiation therapy (IMRT) plans in the two-headed mode of the ViewRay$^{TM}$ system in comparison with that of the normal operation treatment plan of the machine. For this study, a total of eight IMRT plans and corresponding verification plans were generated (four head and neck, two liver, and two prostate IMRT plans). The delivered dose distributions were measured using ArcCHECK$^{TM}$ with the insertion of an ionization chamber. We measured the delivered dose distributions in three-headed mode (normal operation of the machine), two-headed mode with head 1 disabled, two-headed mode with head 2 disabled, and two-headed mode with head 3 disabled. Therefore, a total of four measurements were performed for each IMRT plan. The global gamma passing rates (3%/3 mm) in three-headed mode, head 1 disabled, head 2 disabled, and head 3 disabled were $99.9{\pm}0.1%$, $99.8{\pm}0.3%$, $99.6{\pm}0.7%$, and $99.7{\pm}0.4%$, respectively. The difference in the gamma passing rates of the three- and two-headed modes was insignificant. With 2%/2 mm, the rates were $96.6{\pm}3.6%$, $97.2{\pm}3.5%$, $95.7{\pm}6.2%$, and $95.5{\pm}4.3%$, respectively. Between three-headed mode and head 3 disabled, a statistically significant difference was observed with a p-value of 0.02; however, the difference was minimal (1.1%). The chamber readings showed differences of approximately 1% between three- and two-headed modes, which were minimal. Therefore, the treatment plan delivery in the two-headed mode of the ViewRay$^{TM}$ system seems accurate and robust.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.159.1-159.1
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• 2003

This study deals with the radiation protection effect of the pretreatment of $\beta$-carotene and combination with selenium on the DNA damage in mice after whole body ${\gamma}$-irradiation. This was obtained the radioprotective effect by evaluation of DNA damage levels in mice spleen and blood after irradiation. Six-week-old ICR male mice were administrated with $\beta$-carotene and combination with selenium orally once a day for 5 days and then irradiated with 8.0 Gy of $\gamma$-ray at a dose rate of 1.0 Gy/min. (omitted)