• 제목/요약/키워드: Dose Attenuation

검색결과 171건 처리시간 0.021초

해수산 클로렐라(Chlorella ellipsoidea) 유기용매 추출물의 항염증 효과 (Anti-Inflammatory Effect of Chlorella ellipsoidea Extracted from Seawater by Organic Solvents)

  • 최유진;조월순;김현지;남병혁;강은영;오수정;이계안;정민호
    • 한국수산과학회지
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    • 제43권1호
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    • pp.39-45
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    • 2010
  • Chlorella has been reported to have certain beneficial physiological effects, including hypocholesterolemic, antihypertensive, antioxidative, and anti-tumor activities in animal and human studies. The aim of this study was to determine the anti-inflammatory activities of an 80% methanol extract(CE-Met), hexane fraction (CE-Hex), and ethyl acetate fraction (CE-EA) of Chlorella ellipsoidea in lipopolysaccharide (LPS)-stimulated RAW 264.7 murine macrophage. Treatment with various concentrations of the C. ellipsoidea extract resulted m a significant, dose-dependent reduction in nitric oxide (NO) production by LPS-induced macrophages. The C. ellipsoidea extract significantly inhibited LPS-induced NO production accompanied by an attenuation of IL-6 and TNF-$\alpha$ formation in macrophages. These results suggest potent inhibit이y effects on the production of inflammatory mediators by a C. ellipsoidea extract. Thus, C. ellipsoidea extract may be a potent anti-inflammatory agent for troubled skin.

Overexposed Accidents due to Erroneous Input to Treatment Planning System in Japan

  • Tabushi, Katsuyoshi;Endo, Masahiro;Ikeda, Hiroshi;Uchiyama, Yukio;Hoshina, Masao;Nakagawa, Keiichi;Sakai, Kunio
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.11-12
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    • 2002
  • Accidental overexposures by radiotherapy have gathered attention recently in Japan. The widely publicized accidents have occurred at the government official benefit society hospital and at the hospital affiliated to a medical school. The accident at the government official benefit society hospital occurred when one of two existing accelerators was renewed. A radiotherapy planning system was also introduced at that time. Then treatment planning for the old and the new linear accelerator was performed using the system. There were variations in wedge factors for the 30 degrees wedge filter between the old and the new linear accelerator. That is, the difference in the structure of the wedge filter (30 degrees) resulted in variations of the wedge factors between both accelerators. In order to keep strength, a lead board was backed to the lead wedge filter for the new linear accelerator, whereas the wedge filter for the old one was made of the iron. The X-ray attenuation of the iron wedge filter is smaller than that of the lead wedge filter. The basic beam data of the old linear accelerator, however, wasn't delivered properly between the user and the maker. Then, the accident took place because the same wedge factor was used for the old and the new linear accelerator. On the other hand, the accident which occurred at the university hospital was brought about by the input mistake in initialization of the computer system when a linear accelerator was introduced. The input mistake was found when the software of the system was updated. If the dose had been measured and confirmed adequately, the accidents could have been prevented in both cases.

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In Vivo Effects of Lead on Erythrocytes Following Chronic Exposure through Drinking Water

  • Lee, Moo-Yeol;Shin, Jung-Hun;Han, Hee-Shim;Chung, Jin-Ho
    • Archives of Pharmacal Research
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    • 제29권12호
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    • pp.1158-1163
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    • 2006
  • More than 95% of lead, a environmental heavy metal, entering into blood accumulates in erythrocytes suggesting erythrocytes as an important target of lead toxicity. Recent studies reported that erythrocytes could contribute to blood coagulation via phosphatidylserine (PS) exposure in erythrocytes. However, in vivo effects of chronic lead exposure especially by drink-ing water on procoagulant activity of erythrocytes have not been studied yet. In the present study, we investigated the effects of chronic exposure of lead by drinking water on erythrocytes in rats. Groups of 40 male rats were provided with drinking water containing various concentrations of lead for 4 weeks and complete blood cell count, procoagulant activities of erythrocytes and platelets were evaluated with basic inspections on body weight and food/water consumption. The administration of lead containing drinking water increased the blood lead level (BLL) in a dose-dependent manner up to $22.39{\pm}2.26\;{\mu}g/dL$. Water consumption was significantly decreased while food consumption or body weight gain was not affected. In contrast to the previous findings with acute lead exposure, chronic lead exposure failed to increase PS exposure in erythrocytes with statistical significance although some trends of enhancement were observed. It implies that a certain adaptation might have happened in body during repeated exposure to lead, resulting in attenuation of PS exposure. With this study, we believe that a valuable information was provided for the study on the toxicological significance and the risk assessment of lead contaminated drinking water.

예쁜꼬마선충을 이용한 돼지감자의 수명 연장 효능 (Lifespan Extending Effects of Helianthus tuberosus Linne in C. elegans)

  • 이병주;윤영진;오종우;박지원;이현주;김용성;차동석;권진;오찬호;전훈
    • 생약학회지
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    • 제47권3호
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    • pp.280-286
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    • 2016
  • Helianthus tuberosus Linne (Compositae) has been widely used as a folk remedy to treat various ailments including fever, bleeding, fracture and contusion. This study was designed to elucidate the lifespan extending activities MeOH extract of the tubers of Helianthus tuberosus Linne (MHT) using Caenorhabditis elegans (C. elegans) model system. In the current study, we found that the lifespan of worms was significantly extended by MHT supplement, dose-dependently. MHT also provided robust protection against various stress environments such as osmotic, thermal and oxidative condition. In addition, elevated antioxidant enzyme activities by MHT resulted in attenuation of intracellular reactive oxygen spices (ROS) levels, suggesting antioxidant capacity of MHT might be associated with longevity properties. Herein, we showed that altered food intake and growth of worms were also involved in the MHT activity. Furthermore, MHT increased body movement in aged worms, indicating possible role for MHT in healthspan.

홍화(紅花) 추출물의 항산화 효과에 대한 연구 (Studies on the antioxidant Effects of Carthami Flos Extract)

  • 유진숙;임형호
    • 대한한의학회지
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    • 제28권1호통권69호
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    • pp.137-147
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    • 2007
  • Objective : The objective of this study was to investigate the antioxidative effects of Carthami Flos extract. Methods : Total antioxidant status was examined by total antioxidant capacity(TAC) and total antioxidant response(TAR) against potent free radical reactions. The effect of Carthami Flos extract was examined far details of total phenolic content concentration at which 1,1-dipheny1-2-picrylhydrazyl(DPPH) radical scavenging activity was inhibited, the inhibitory effect on lipid peroxidation, and the effect on reactive oxygen species(ROS) generation. Results : TAC of Carthami Flos extract at the concentration of 5 mg/ml was 1.84 mM Trolox equivalent. 2. TAR of Carthami Flos extract, on the other hand, couldn't be determined due to interference from unidentified compounds. 3. Total phenolic content of Carthami Flos extract at the concentration of 5 mg/ml was 2.01 mM gallic acid equivalent. 4. Concentration of Carthami Flos extract at which DPPH radical scavenging activity was inhibited by 50% was 6.43 mg/ml as compared to 100% by Pyrogallol solution as a reference. 5. The inhibitory effect of the extract on lipid peroxidation was examined using rat liver mitochondria induced by FeS04/ascorbic acid. Carthami Flos extract at the concentration of 10 ms/ml slightly but significantly decreased TBARS concentration. The extract continued to prevent lipid peroxidation in a dose-dependent manner. 6. The effect of Carthami Flos extract on reactive oxygen species(ROS) generation was examined using a cell-free system induced by hydrogen peroxide/FeS04. Addition of 1 mg/ml of Carthami Flos extract significantly reduced dichlorofluorescein(DCF) fluorescence. Carthami Flos extract caused concentration-dependent attenuation of the increase in DCF fluorescence, indicating that the ektract significantly prevented ROS generation in vitro. Conclusion: : Antioxidant efffcts of Carffami ffor extract seem to be due, at least in part, to the prevention offree radical-induced oxidation, fellowed by inhibition of lipid peroxidation.

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상엽(桑葉)추출물의 항산화효과에 대한 연구 (Studies on the Antioxidant Effects of Mori Folium Extract)

  • 이지은;임형호;송윤경
    • 대한한의학회지
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    • 제28권1호통권69호
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    • pp.148-158
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    • 2007
  • Objective : The objective of this study was to investigate the antioxidant effects of Mori Folium extract. Methods Total antioxidant status was examined by total antioxidant capacity(TAC) and total antioxidant response(TAR) against potent free radical reactions. The effect of Mori Folium extract was examined by measuring total phenolic content, concentration at which 1,1-dipheny1-2-picrylhydrazyl(DPPH) radical scavenging activity was inhibited, inhibitory effect on lipid peroxidation, and the effect on reactive oxygen species(ROS) generation. Results : 1. TAC and TAR of Mori Folium extract at the concentration of 5 mg/ml were 1.61 and 1.24 mM Trolox equivalents, respectively. 2. Total phenolic content of Mori Folium extract at the concentration of 5 mg/Ml was 1.70 mM gallic acid equivalent. 3. Concentration of Mori Folium extract at which DPPH radical scavenging activity was inhibited by 50% was 2.29 m9/m4 as compared to 100% by Pyrogallol solution as a reference. 4. The inhibitory effect of the extract on lipid peroxidation was examined using rat liver mitochondria induced by FeSO$_4$/ascorbic acid. Mori Folium extract at the concentration of 10 mg/ml significantly decreased thiobarbituric acid reactive substances(TBARS) concentration. The extract prevented lipid peroxidation in a dose-dependent 5. The effect of Mori Folium extract on reactive oxygen species(ROS) generation was examined using a celt-free system induced by hydrogen peroxide FeSO$_4$. Addition of 1 mg/ml of Mori Folium extract significantly reduced dichlorofluorescein(DCf) fluorescence. The extract caused concentration-dependent attenuation of the increase in DCF fluorescence, indicating that the extract significantly prevented ROS generation in vitro. Conclusion ; The antioxidant effects of Mori Folium extract seem to be due, at least in part, to the prevention offree radical-induced oxidation, fllowed by inhibition of lipid peroxidation.

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Attenuation of Morphine Tolerance and Withdrawal Syndrome by Coadministration of Nalbuphine

  • Jang, So-Yong;Kim, Hee-Jeong;Kim, Dong-Hyun;Jeong, Myeon-Woo;Ma, Tangen;Kim, Seong-Youl;Ho, Ing K.;Oh, Sei-Kwan
    • Archives of Pharmacal Research
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    • 제29권8호
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    • pp.677-684
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    • 2006
  • Morphine has been used widely on the treatment of many types of chronic pain. However the development of tolerance to and dependence on morphine by repeat application is a major problem in pain therapy. The purpose of the present study was to investigate whether combined administration of nalbuphine with morphine affects the development of tolerance to and dependence on morphine. We hypothesize that the use of nalbuphine, ${\kappa}-agonist$ may prove to be useful adjunct therapy to prevent morphine-induced undesirable effects in the management of some forms of chronic pain. Morphine (10 mg/kg) was injected to rats intraperitoneally for 5 day. The variable dose of nalbuphine (0.1, 1.0 and 5.0 mg/kg) was administered (i.p.) in combination with morphine injection. The development of morphine tolerance was assessed by measuring the antinociceptive effect with the Randall-Selitto apparatus. The development of dependence on morphine was determined by the scoring the precipitated withdrawal signs for 30 min after injection of naloxone (10 mg/kg, i.p.). Nalbuphine did not attenuate antinociceptive effect of morphine in rats. Interestingly, combined administration of morphine with nalbuphine (10:1) significantly attenuated the development of dependence on morphine. The elevation of $[^3H]MK-801$ binding in frontal cortex, dentate gyrus, and cerebellum after chronic morphine infusion was suppressed by the coadministration of nalbuphine. In addition, the elevation of NR1 expression by morphine was decreased by the coadministration of nalbuphine in rat cortex. These results suggest that the coadministration of nalbuphine with morphine in chronic pain treatment can be one of therapies to reduce the development of tolerance to and dependence on morphine.

Split-bolus CT urography with synchronous nephrographic and excretory phase in dogs: comparison of image quality with three-phase CT urography and optimal allocation ratio of contrast medium

  • Je, Hyejin;Lee, Sang-Kwon;Jung, Jin-Woo;Jang, Youjung;Chhoey, Saran;Choi, Jihye
    • Journal of Veterinary Science
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    • 제21권4호
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    • pp.55.1-55.11
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    • 2020
  • Background: Computed tomography urography (CTU), based on the excretion of contrast medium after its injection, allows visualization of the renal parenchyma and the renal collecting system. Objectives: To determine the optimal contrast medium dose allocation ratio to apply in split-bolus CTU in dogs. Methods: This prospective, experimental, exploratory study used 8 beagles. In 3-phase CTU, unenhanced-, nephrographic-, and excretory-phase images were obtained with a single injection of 600 mg iodine/kg iohexol. In split-bolus CTU, two different contrast medium allocation ratios (30% and 70% for split CTU 1; 50% and 50% for split CTU 2) were used. Unenhanced phase image and a synchronous nephrographic-excretory phase image were acquired. Results: Although the attenuation of the renal parenchyma was significantly lower when using both split CTUs than the 3-phase CTU, based on qualitative evaluation, the visualization score of the renal parenchyma of split CTU 1 was as high as that of the 3-phase CTU, whereas the split CTU 2 score was significantly lower than those of the two others. Artifacts were not apparent, regardless of CTU protocol. The diameter and opacification of the ureter in both split CTUs were not significantly different from those using 3-phase CTU. Conclusions: Split-bolus CTU with a contrast medium allocation ratio of 30% and 70% is feasible for evaluating the urinary system and allows sufficient enhancement of the renal parenchyma and appropriate distention and opacification of the ureter, with similar image quality to 3-phase CTU in healthy dogs. Split-bolus CTU has the advantages of reducing radiation exposure and the number of CT images needed for interpretation.

갑상샘 스캔 정량분석을 통한 갑상샘 섭취율 동시계측법 연구 (Study of Simultaneous Counting of Thyroid Uptake with Quantitative Analysis of Thyroid Scans)

  • 김정수;김근우
    • 대한방사선기술학회지:방사선기술과학
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    • 제46권5호
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    • pp.401-408
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    • 2023
  • Thyroid uptake measurements can be subject to measurement errors due to the scoping and positioning of the thyroid gland. To compensate for these limitations, the clinical utility of the thyroid simultaneous counting method as an alternative to thyroid uptake measurement was analyzed and evaluated experimentally through quantitative analysis of images acquired after thyroid scanning. Experimental data were obtained using a Gamma camera (GE infinia), a thyroid uptake system (KOROID 1), and a thyroid neck phantom. Based on the thyroid uptake rate of 1-5% according to the protocol of thyroid scan test (99mTcO4 - , 370 MBq) in normal results, 99mTcO4 - was set in the range of 3.7-18.5 MBq (Matrix: 256×256, Scan time: 1 min, collimator: pin hole, phantom-collimator distances: 7 cm). The acquired images were corrected for the attenuation of isotopes due to the set-up time and half-life by applying the Auto Region of interest (ROI) drawing system, and the significance of the experimental results was evaluated by Multiple linear regression analysis (SPSS, ver. 22, IBM). The thyroid uptake rate showed a significant correlation between the dose and the measured counts when using the thyroid uptake system equipment. Meanwhile, the quantitative analysis counts of phantom images using Gamma camera also showed a significant correlation. Thus confirmed that the correlation between these two experiments was statistically significant (P<0.05). The simultaneous counting protocol, which indirectly measures thyroid uptake from thyroid scans, is likely to be clinically relevant if complemented by additional studies with different variables in patients with thyroid disease.

Enhancing Gamma-Neutron Shielding Effectiveness of Polyvinylidene Fluoride for Potent Applications in Nuclear Industries: A Study on the Impact of Tungsten Carbide, Trioxide, and Disulfide Using EpiXS, Phy-X/PSD, and MCNP5 Code

  • Ayman Abu Ghazal;Rawand Alakash;Zainab Aljumaili;Ahmed El-Sayed;Hamza Abdel-Rahman
    • Journal of Radiation Protection and Research
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    • 제48권4호
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    • pp.184-196
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    • 2023
  • Background: Radiation protection is crucial in various fields due to the harmful effects of radiation. Shielding is used to reduce radiation exposure, but gamma radiation poses challenges due to its high energy and penetration capabilities. Materials and Methods: This work investigates the radiation shielding properties of polyvinylidene fluoride (PVDF) samples containing different weight fraction of tungsten carbide (WC), tungsten trioxide (WO3), and tungsten disulfide (WS2). Parameters such as the mass attenuation coefficient (MAC), half-value layer (HVL), mean free path (MFP), effective atomic number (Zeff), and macroscopic effective removal cross-section for fast neutrons (ΣR) were calculated using the Phy-X/PSD software. EpiXS simulations were conducted for MAC validation. Results and Discussion: Increasing the weight fraction of the additives resulted in higher MAC values, indicating improved radiation shielding. PVDF-xWC showed the highest percentage increase in MAC values. MFP results indicated that PVDF-0.20WC has the lowest values, suggesting superior shielding properties compared to PVDF-0.20WO3 and PVDF-0.20WS2. PVDF-0.20WC also exhibited the highest Zeff values, while PVDF-0.20WS2 showed a slightly higher increase in Zeff at energies of 0.662 and 1.333 MeV. PVDF-0.20WC has demonstrated the highest ΣR value, indicating effective shielding against fast neutrons, while PVDF-0.20WS2 had the lowest ΣR value. The Monte Carlo N-Particle Transport version 5 (MCNP5) simulations showed that PVDF-xWC attenuates gamma radiation more than pure PVDF, significantly decreasing the dose equivalent rate. Conclusion: Overall, this research provides insights into the radiation shielding properties of PVDF mixtures, with PVDF-xWC showing the most promising results.