• Title/Summary/Keyword: Low-dose irradiation

Search Result 396, Processing Time 0.029 seconds

Comparative Study of the Effective Dose from Panoramic Radiography in Dentistry Measured Using a Radiophotoluminescent Glass Dosimeter and an Optically Stimulated Luminescence Detector

  • Lee, Kyeong Hee;Kim, Myeong Seong;Kweon, Dae Cheol;Choi, Jiwon
    • Journal of the Korean Physical Society
    • /
    • v.73 no.9
    • /
    • pp.1377-1384
    • /
    • 2018
  • Accurate measurement of the absorbed dose and the effective dose is required in dental panoramic radiography involving relatively low energy with a rotational X-ray tube system using long exposures. To determine the effectiveness of measuring the irradiation by using passive dosimetry, we compared the entrance skin doses by using a radiophotoluminescent glass dosimeter (RPL) and an optically stimulated luminescence detector (OSL) in a phantom model consisting of nine and 31 transverse sections. The parameters of the panoramic device were set to 80 kV, 4 mA, and 12 s in the standard program mode. The X-ray spectrum was applied in the same manner as the panoramic dose by using the SpekCalc Software. The results indicated a mass attenuation coefficient of $0.008226cm^2/g$, and an effective energy of 34 keV. The equivalent dose between the RPL and the OSL was calculated based on a product of the absorbed doses. The density of the aluminum attenuators was $2.699g/cm^3$. During the panoramic examination, tissue absorption doses with regard to the RPL were a surface dose of $75.33{\mu}Gy$ and a depth dose of $71.77{\mu}Gy$, those with regard to the OSL were surface dose of $9.2{\mu}Gy$ a depth dose of $70.39{\mu}Gy$ and a mean dose of $74.79{\mu}Gy$. The effective dose based on the International Commission on Radiological Protection Publication 103 tissue weighting factor for the RPL were $0.742{\mu}Sv$, $8.9{\mu}Sv$, $2.96{\mu}Sv$ and those for the OSL were $0.754{\mu}Sv$, $9.05{\mu}Sv$, and $3.018{\mu}Sv$ in the parotid and sublingual glands, orbit, and thyroid gland, respectively. The RPL was more effective than the OSL for measuring the absorbed radiation dose in low-energy systems with a rotational X-ray tube.

Changes of Microbiological and Physicochemical Characteristics of Doenjang Prepared with Low Salt Content and Gamma Irradiation (감마선 조사와 저염함량으로 제조한 된장의 미생물 및 품질특성 변화)

  • Park, Byoung-Jun;Jang, Kyu-Sub;Kim, Dong-Ho;Yook, Hong-Sun;Byun, Myung-Woo
    • Korean Journal of Food Science and Technology
    • /
    • v.34 no.1
    • /
    • pp.79-84
    • /
    • 2002
  • Changes of microbiological and physicochemical characteristics of gamma irradiated Doenjang with low salt were studied. Samples were prepared by mixing the Doenjang and the Chungkukjang with 6% and 8% of salinity. The mixture was irradiated by gamma-ray with dose of 0, 5, 10, 20 kGy, and each sample was stored at $25^{\circ}C$ for 8 weeks. The results showed that the Bacillus cell was inactivated by $10^4-10^5\;cells/g$ with dose of 10 kGy, and yeast and Lactobacillus group were nearly eliminated by 10 kGy. The general quality of gamma irradiated low salt Doenjang, such as amino nitrogen, protease activity, and pH, were more stable than that of control during storage periods. The sensory evaluations showed that 8% (salt)-5 kGy and 6% (salt)-10 kGy irradiated samples were more acceptable than market purchased Doenjang. Therefore, it was considered that gamma irradiation was effective for maintaining better quality of low salt Doenjang and suitable radiation dose was 5 kGy in 8% salted, and 10 kGy in 6% salted sample.

The Radioprotective Effects of Bu-Zhong-Yi-Qi-Tang as a Prescriptions of Traditional Chinese Medicine in Irradiated Mice

  • Kim, Sung-Ho;Kim, Se-Ra;Heon Oh;Yang, Jung-Ah;Jo, Sung-Kee;Byun, Myung-Woo;Yee, Sung-Tae
    • Proceedings of the Korean Society of Veterinary Pathology Conference
    • /
    • 2000.09a
    • /
    • pp.21-21
    • /
    • 2000
  • We performed this study to determine the effect of Bu-Zhong-Yi-Qi-Tang, as a prescription of traditional Oriental medicine, and its major ingredients on jejunal crypt survival, endogenous spleen colony formation, and apoptosis in jejunal crypt cells of mice irradiated with high and low dose of r-radiation. Bu-Zhong-Yi-Qi-Tang administration before irradiation protected the jejunal crypts (p<0.0001), increased the formation of endogenous spleen colony (p<0.05) and reduced the frequency of radiation-induced apoptosis (p<0.05). (omitted)

  • PDF

Effect of Gamma Irradiation on Egg White Protein (卵白단백질에 대한 감마선 조사의 영향)

  • 변명우;임성일;육홍선;윤혜현;김영지
    • Journal of the Korean Society of Food Science and Nutrition
    • /
    • v.27 no.2
    • /
    • pp.291-295
    • /
    • 1998
  • The ovalbumins obtained from hen's and duck's egg white were irradiated with up to 100 kGy at room temperature. The purified proteins were evaluated for their in vitro digestibility by incubating successively with pepsin and pancreatin conjugate. Amino acid compositions and SDS-PAGE pattern in these proteins were also analyzed. The obtained results indicated that gamma irradiation within the tested dose range(up to 100kGy) produced no statistically significant changes in the in vitro digestibility an amino acid compositions. Analysis of gamma-irradiated ovalbumins by SDS-PAGE revealed radiolysis of ovalbumin into proteins or peptides of low molecular weights.

  • PDF

Effects of Ultraviolet Blood Irradiation in a Type 1 Diabetic Rabbit (제1형 당뇨토끼에서 자외선 혈액 조사 효과)

  • Yang, Yeong-Seok;Kim, Gi-Beum
    • Journal of Biomedical Engineering Research
    • /
    • v.40 no.3
    • /
    • pp.81-96
    • /
    • 2019
  • The purpose of this study is to evaluate the effects of ultraviolet blood irradiation on the blood when a low dose of ultraviolet (UV) C is directly irradiated to the blood in a diabetic rabbit model and to evaluate the effects on treatment for diabetes. This study results indicate that the reduced body weight is increased and blood glucose levels are significantly reduced after the UBI treatment is performed when compared to those prior to the UBI treatment. In addition, $HCO_3{^-}$ levels and blood pH were elevated and lowered, respectively. When the UBI treatment is performed in a diabetic rabbit model, in this result indicate that blood glucose levels are reduced.

A Study on the Color Removal in the Secondary Effluent (하수처리장 방류수 색도 제거에 관한 연구)

  • 이면주;정영도;진준하
    • Journal of environmental and Sanitary engineering
    • /
    • v.13 no.3
    • /
    • pp.30-36
    • /
    • 1998
  • A study on the color removal by irradiation of ${\gamma}-ray$ was carried out to reclaim the secondary effluent for the purpose of industrial water. Coagulation, ozone and ion exchange methods were compared. It could know that irradiation method was the most effective in color removal. The color was removed by 87.5% at 0.5 Mrad and it was increase with dose. High removal efficiency could be obtained in low pH and low concentration of $CO3^{-2}$. This process can be applied to the treatment of secondary effluent and is considered to be one of the most useful tertiary treatment.

  • PDF

Radiation-Induced Grafting of Acrylic Acid onto Polypropylene Fabric in the Presence of Metallic Salt (폴리프로필렌 부직포에 아크릴산의 방사선 그라프트 반응에서 금속염의 효과)

  • Nho, Young Chang;Park, Jong Shin;Jin, Joon-Ha
    • Applied Chemistry for Engineering
    • /
    • v.7 no.5
    • /
    • pp.946-953
    • /
    • 1996
  • The effect of absorbed dose, dose rate, cationic salts and solvent on the grafting yield was evaluated when acrylic acid was grafted onto polypropylene fabric by simultaneous irradiation process. Low dose rate when irradiated with the same absorbed dose led to a high grafting yield. On the other hand, the grafting yield increased with dose rate in case the total irradiation times is equal, and the initial rate of grafting was found to be proportional to be 0.74 power of dose rate. $FeSO_4{\cdot}7H_2O$ was found to be the most effective additive for high grafting yield, while inhibiting homopolymer formation. It was impossible to induce radiation grafting without the addition of the certain amount of salt, but the grafting yield decreased with increasing metallic salt.

  • PDF

Effects of High-Protein Diet and/or Resveratrol Supplementation on the Immune Response of Irradiated Rats

  • Kim, Kyoung Ok;Park, Hyunjin;Kim, Hyun-Sook
    • Preventive Nutrition and Food Science
    • /
    • v.19 no.3
    • /
    • pp.156-163
    • /
    • 2014
  • We investigated the effects of a high-protein diet and resveratrol supplementation on immune cells changes induced by abdominal irradiation in rats. Female Wistar rats were divided into 5 groups: 1) control diet, 2) control diet with irradiation 3) 30% high-protein diet with irradiation, 4) normal diet with resveratrol supplementation and irradiation, and 5) 30% high-protein diet with resveratrol supplementation and irradiation. We measured blood protein and albumin concentrations, lipid profiles, white blood cell (WBC) counts, proinflammatory cytokine production, and splenocyte proliferation in rats that had been treated with a 17.5 Gy dose of radiation 30 days prior. A high-protein diet affected plasma total cholesterol and very low density lipoprotein-cholesterol levels, which were increased by the radiation treatment. In addition, the lymphocyte percentage and immunoglobulin M (IgM) concentration were increased, and the neutrophil percentage was decreased in rats fed a high-protein diet. Resveratrol supplementation decreased the triglyceride (TG) level, but increased the IgM concentration and splenocyte proliferation. Proinflammatory cytokine production was lower in rats fed a high-protein diet supplemented with resveratrol than in rats fed a control diet. The results of the present study indicate that high-protein diets, with or without resveratrol supplementation, might assist with recovery from radiation-induced inflammation by modulating immune cell percentages and cytokine production.

Physical and Microbiological Approach in Proving the Identity of Gamma-irradiated Different Teas

  • Kausar, Tusneem;Kim, Byeong-Keun;Kim, Dong-Ho;Kwon, Joong-Ho
    • Food Science and Biotechnology
    • /
    • v.14 no.1
    • /
    • pp.1-5
    • /
    • 2005
  • Photostimulated luminescence (PSL), thermoluminescence (TL), electron spin resonance (ESR), and direct epiflourescent filter technique/aerobic plate count (DEFT/APC) were applied to detect dried green, black, and oolong teas irradiated between 0-10 kGy. Teas irradiated at 2.5 kGy and higher showed over 5000 photon counts/60 sec, while non-irradiated teas yielded 650-1000 photon counts/60 sec. TL glow curves for minerals separated from teas were detected at about $300^{\circ}C$ with low intensity in non-irradiated samples, whereas around $150^{\circ}C$ with high intensity in all irradiated samples. Ratio of $TL_1/TL_2$ based on re-irradiation step, showing lower than 0.1 and higher than 1.44 for non-irradiated and irradiated samples, respectively, enhanced reliability of TL results. ESR measurements for irradiated teas showed signals specific to irradiation. Log DEFT/APC ratio increased with irradiation dose; this result could be applied to identify irradiated tea samples.

Effect of Gamma Ray on Molecular Structures of Alkali-Lignin (감마선이 알칼리 리그닌의 분자구조에 미치는 영향)

  • Kim, Du Yeong;Jeun, Joon Pyo;Shin, Hye Kyoung;Kang, Phil Hyun
    • Journal of Radiation Industry
    • /
    • v.5 no.3
    • /
    • pp.249-252
    • /
    • 2011
  • Lignin is one of the natural macromolecules. Every year large amount of lignin arises from the cellulose production as a by-product worldwide. The use of lignin as a precursor to carbonaceous materials has gained interest due to its low cost and high availability. Therefore, we improved the properties of alkali-lignin by exposing to gamma ray in this study. The alkali-lignin is irradiated by Gamma ray irradiation with varying doses. The char yields of alkali-lignin were investigated by increasing up to 50 kGy. The cross-linking and bond scission of alkali-lignin occur simultaneously during gamma ray irradiation. The crosslinking was predominantly accelerated by gamma ray irradiation up to 50 kGy. Bond scission predominantly occurs between 50 and 500 kGy. ESCA analysis indicated that the alcoholic carbon increase up to 50 kGy. Solution viscosity was increased as absorbed dose increased up to 20 kGy. In addition, the aromatic ring was not influenced by irradiation at doses ranging from 20 to 500 kGy as shown in FT-IR results.