• Title/Summary/Keyword: Irradiation Dose

Search Result 1,987, Processing Time 0.029 seconds

Biological Effects Of Blood And Testis By Abdominal Irradiation With Neutron Or Gamma-ray In Black Mouse

  • Chun, Ki-Jung;Yoo, Bo-Kyung
    • Proceedings of the PSK Conference
    • /
    • 2003.10b
    • /
    • pp.109.1-109.1
    • /
    • 2003
  • The aim of this study was to investigate the biological effects of blood and testis by neutron or gamma-ray irradiation in black mouse. Six-week-old C57BL male mice were irradiated with neutron (flux: 1.036739E+09) or Co60 gamma rays(dose rate: lGy/min.) The irradiation method of animal was abdominal irradiation and dose of irradiation was 10 and 20 Gy added with 5 and 15Gy in neutron irradiation.. After that, the mice were sacrificed 3 days later. Blood and testis were taken and then composition of blood in blood cell were investigated. (omitted)

  • PDF

Understanding Phytosanitary Irradiation Treatment of Pineapple Using Monte Carlo Simulation

  • Kim, Jongsoon;Kwon, Soon-Hong;Chung, Sung-Won;Kwon, Soon-Goo;Park, Jong-Min;Choi, Won-Sik
    • Journal of Biosystems Engineering
    • /
    • v.38 no.2
    • /
    • pp.87-94
    • /
    • 2013
  • Purpose: Pineapple is now the third most important tropical fruit in world production after banana and citrus. Phytosanitary irradiation is recognized as a promising alternative treatment to chemical fumigation. However, most of the phytosanitary irradiation studies have dealt with physiochemical properties and its efficacy. Accurate dose calculation is crucial for ensuring proper process control in phytosanitary irradiation. The objective of this study was to optimize phytosanitary irradiation treatment of pineapple in various radiation sources using Monte Carlo simulation. Methods: 3-D geometry and component densities of the pineapple, extracted from CT scan data, were entered into a radiation transport Monte Carlo code (MCNP5) to obtain simulated dose distribution. Radiation energy used for simulation were 2 MeV (low-energy) and 10 MeV (high-energy) for electron beams, 1.25 MeV for gamma-rays, and 5 MeV for X-rays. Results: For low-energy electron beam simulation, electrons penetrated up to 0.75 cm from the pineapple skin, which is good for controlling insect eggs laid just below the fruit surface. For high-energy electron beam simulation, electrons penetrated up to 4.5 cm and the irradiation area occupied 60.2% of the whole area at single-side irradiation and 90.6% at double-side irradiation. For a single-side only gamma- and X-ray source simulation, the entire pineapple was irradiated and dose uniformity ratios (Dmax/Dmin) were 2.23 and 2.19, respectively. Even though both sources had all greater penetrating capability, the X-ray treatment is safer and the gamma-ray treatment is more widely used due to their availability. Conclusions: These results are invaluable for optimizing phytosanitary irradiation treatment planning of pineapple.

Comparison of Distribution following Treatment Method in Total Body Irradiation (전신방사선조사에서 치료방법에 따른 선량분포 특성 비교)

  • 김성규;김명세;신세원
    • Progress in Medical Physics
    • /
    • v.6 no.2
    • /
    • pp.21-28
    • /
    • 1995
  • In recent years there has been a growing interest in total body irradiation. For refractory leukemia or lymphoma patients, varions techniques and dose regimens were intridused, including high dose total body irradiation for destruction of leukemic or bone marrow cells and immunosupperression prior to bone marrow transplantation. Accurate provision for specified dose and the desired homogeneity are essential before clinical total body irradiatio. When performed in total body irradiation, the problem obtain uniform uniform dose distribution in brain, neck, lung, umbilicus, pelvis and leg. Authors compared to dose distribution with method 1 and method 1. The method 1 used compensationg filters for homogeneous dose distribution(Minesota University Method). The method 2 used fixing frame made in acryl developing authors. Results were following 1. Method 1 was showed dose distribution from 95.6% to 100%, method 2 showed dose distribution from 95.4% to 100% 2. Method 2 was showed different to 3.4% at skin region and midline in the brain. In the neck, showed different to 1.5%. In the umbilicus, showed different to 2.3%.

  • PDF

Albumin-Crosslinked PVP Hydrogel as a Gastric Retention Platform (위내체류를 목적으로 한 알부민 가교 PVP 하이드로겔의 팽윤특성)

  • Shim, Chang-Koo;Yeo, So-Hyeon
    • Journal of Pharmaceutical Investigation
    • /
    • v.23 no.3
    • /
    • pp.145-153
    • /
    • 1993
  • Retaining a drug in the stomach by some means is sometimes necessary to extend the G1 absorption time of the drug more than 6-8 hrs. Hydrogel has often been examined for its feasibility as a dosage form, so called platform, that could be retained in the stomach due to its excellent swelling properties in the gastric fluid. In this study, polyvinylpyrrolidone (PVP) hydrogel crosslinked by albumin or acrylated albumin was synthesized in a tablet form and evaluated for its possibility as the platform. The synthesis of the hydrogel was performed by $^{60}Co\;{\gamma}-ray$ irradiation of N-vinyl-2-pyrrolidone (monomer) in the presence of a crosslinking agent: aqueous solution of albumin or acrylated albumin. Synthetic conditions such as radiation dose, dose rate and concentration of crosslinking agent were varied in order to optimize the swelling and mechanical properties of the hydrogels. Degree of swelling of albumin-crosslinked PVP (Al-PVP) was highly dependent on radiation dose, dose rate and albumin concentration: it was decreased as they increased. On the other hand, that of acrylated albumin-crosslinked PVP (Acryl-PVP) was almost independent on them except dose rate: it was decreased as the radiation dose rate increased. The compressive strength of the two hydrogels was decreased as the dose rate increased. Digestion of both PVP in artificial gastric fluid containing pepsin was delayed by the ${\gamma}-ray$ irradiation. In conclusion, Al-PVP and Acry-PVP with diverse swelling and mechanical properties could be obtained by controlling synthetic conditions, mainly the irradiation dose rate.

  • PDF

An Experimental Study on the Effects of Hyperthermia and Irradiation on the Rat's Kidney (방사선조사와 온열요법이 백서신에 미치는 조직 변화에 관한 실험적 연구)

  • Yoo, Myung-Hee;Lee, Kyung-Ja;Rhee, Chung-Sik
    • Radiation Oncology Journal
    • /
    • v.7 no.2
    • /
    • pp.157-169
    • /
    • 1989
  • Radiological and clinical evidences indicate that hyperthermia combined with irradiation produce a significant improvement in therapeutic effect of cancer The experiences obtained from 90 rats' kidney A single dose of irradiation ranged from 6Gy, 8Gy and 10Gy was delivered on the rat's kidney. The combined therapy group had the same irradiation after hyperthermia at $42\~44^{\circ}C$ for 30 minutes. Microscopic examination and calculation of thermal enhancement ratio were carried out, and the results were as follows: 1. In the group of hyperthermia alone, there were moderate glomerular congestion and mild tubular degeneration on light microscopic examination. 2. In the group of irradiation alone, tubular degeneration was noted in 6Gy irradiation and its severity was increased along with radiation dose. 3. In the group of hyperthermia combined with irradiation, tubular degeneration and necrosis were appeared in 6Gy and 10Gy irradiation, respectively. 4. On electron microscopic examination, proximal convoluted tubular and glomerular changes in irradiation group were similar to that of combined with hyperthermia, and its severity was increased along with observation periods. 5. Thermal enhancement ratio (TER) was 1.0 after evaluation of histipathologic changes in rat's kidney, with combination therapy.

  • PDF

PHYSIOLOGICAL EFFECTS OF GAMMA-RADIATION ON MEIOSIS IN RYE ("감마"일선 조사에 의하여 호밀의 감수분열에 수발된 생리적영향)

  • 이웅직
    • Journal of Plant Biology
    • /
    • v.1 no.2
    • /
    • pp.1-4
    • /
    • 1958
  • 1. A vernalized Korean rye was exposed to Co60 in dose of 150r (dose rate was 7r per minute) and pollen mother cells were examined for cytological study. 2. According to the observation, it is quite clear that scraping of chromosomes soon after irradiation and surface stickiness at the period of 6 hours after irradiation were followed by structural changes at the period of 12 hours after irradiation.

  • PDF

Changes of Microorganism during the Storage of Spices as Affected by Irradiation (방사선 조사한 향신료의 저장중 미생물 변화)

  • 이병우;김형찬
    • Food Science and Preservation
    • /
    • v.2 no.1
    • /
    • pp.203-207
    • /
    • 1995
  • Spices(Tumeric, Celery-seed, Cumin, Black pepper, Coriander) were irradiated at dose levels of 0, 5, 7 and 9kGy using Co60 source and stored at room temperature. After 12 months of storage following 9kGy irradiated spice, total aerobic bacteria were significantly decreased. When the irradiation dose was 7kGy, microbial levels showed l02-103 levels. However, total lactic acid bacteria and E-coli were shown negative at below 5kGy.

  • PDF

Bioassay in BALB/c mice exposed to low dose rate radiation (저선량율 방사선 조사한 BALB/c 마우스에서의 영향평가)

  • Kim, Sung-Dae;Gong, Eun-Ji;Bae, Min-Ji;Yang, Kwang-Mo;Kim, Joong-Sun
    • Journal of Radiation Protection and Research
    • /
    • v.37 no.3
    • /
    • pp.159-166
    • /
    • 2012
  • The present study was performed to investigate the toxicity of low-dose-rate irradiation in BALB/c mice. Twenty mice of each sex were randomly assigned to four groups of five mice each and were exposed to 0 (sham), 0.02, 0.2, or 2 Gy, equivalents to low-dose-rate irradiation to 3.49 $mGy{\cdot}h^{-1}$. Urine, blood, and blood biochemistry were analyzed, and organ weight was measured. The low-dose-rate irradiation did not induce any toxicologically significant changes in mortality, clinical signs, body weight, food and water consumption, urinalysis, and serum biochemistry. However, the weights of reproductive organs including the testis, ovary, and uterus decreased in a dose-dependent manner. Irradiation at 2 Gy significantly decreased the testis, ovary, and uterus weights, but did not change the weights of other organs. There were no adverse effects on hematology in any irradiated group and only the number of neutrophils increased dose dependently. The low-dose-rate irradiation exposure did not cause adverse effects in mice at dose levels of 2 Gy or less, but the reproductive systems of male and female mice showed toxic effects.