• Title/Summary/Keyword: Radiological Effects

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Ultrasonic Cavitation Effect Observation Using Bubble Cloud Image Analysis (기포군 영상분석을 통한 초음파 캐비테이션 현상의 변화 관찰)

  • Noh, Si-Cheol;Kim, Ju-Young;Kim, Jin-Su;Kang, Jung-Hoon;Choi, Heung-Ho
    • Journal of Sensor Science and Technology
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    • v.20 no.2
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    • pp.124-130
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    • 2011
  • In this study, in order to evaluate the yield of bubble by ultrasonic cavitation in HIFU sonication, the bubble image analysis was performed. The changing phenomenon of cavitation effect according to the sonication condition was discussed by analyzing the bubble image. Especially the appearance of bubble cloud, the size of micro-bubble, and the yield of bubble were considered. The 500 KHz and 1.1 MHz concave type ultrasonic transducers were used for HIFU sonication. Computer controlled digital camera was used to obtain the bubble image, and the binary image processing(binarization coefficient : 0.15) was performed to analyze them. In results of 500 KHz and 1.1 MHz transducer, the area of bubble cloud was increased in proportion to the rise in sonication intensity($R^2$ : 0.7031 and 0.811). The mean size of single microbubble was measured as 98.18 um in 500 KHz sonication, and 63.38 um in 1.1 MHz sonication. In addition, the amount of produced bubble was increased in proportion to sonication intensity. Through the result of this study and further study for variable image processing method, the quantitative evaluation of ultrasonic cavitation effects in HIFU operation could be possible with the linearity associated with the sonication conditions.

Assessing Correlation between Two Variables in Repeated Measurements using Mixed Effect Models (혼합모형을 이용한 반복 측정된 변수들 간의 상관분석)

  • Han, Kyunghwa;Jung, Inkyung
    • The Korean Journal of Applied Statistics
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    • v.28 no.2
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    • pp.201-210
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    • 2015
  • Repeated measurements on each variables of interest often arise in bioscience or medical research. We need to account for correlations among repeated measurements to assess the correlation between two variables in the presence of replication. This paper reviews methods to estimate a correlation coefficient between two variables in repeated measurements using the variance-covariance matrix of linear mixed effect models. We analyze acoustic radiation force impulse imaging (ARFI) data to assess correlation between three shear wave velocity (SWV) measurements in liver or spleen and spleen length by ultrasonography. We present how to obtain parameter estimates for the variance-covariance matrix and correlations in mixed effects models using PROC MIXED in SAS.

Protective Effects of Leaf and Flower Extracts from Cirsium japonicum var. ussuriense on Oxidative Damage in Normal Human Erythrocytes and Plasma (엉겅퀴(Cirsium japonicum var. ussuriense) 잎 및 꽃 추출물이 정상인 적혈구와 혈장의 산화적 손상에 대한 보호효과)

  • Kang, Hyun-Ju;Mok, Ji-Ye;Cho, Jung-Keun;Jeon, In-Hwa;Kim, Hyeon-Soo;Park, Ji-Min;Jeong, Seung-Il;Shim, Jae-Suk;Jang, Seon-Il
    • Korean Journal of Pharmacognosy
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    • v.43 no.1
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    • pp.66-71
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    • 2012
  • Cirsium japonicum var. ussuriense is often used in treatment of human disease such as hemorrhage, blood congestion and inflammation. This study was accomplished to evaluate the antioxidant properties of the leaf (CLE) and flower (CFE) extracts of C. japonicum var. ussuriense to protect normal human red blood cells (RBC) and plasma samples against oxidative damage in vitro. CLE and CFE were prepared by extracting with hot water. In red blood cells and plasma, oxidative hemolysis and lipid peroxidation induced by the aqueous peroxyl radical generator [2,2'-azobis (2-amidinopropane) dihydrochloride, AAPH] were significantly suppressed by CLE or CFE in a dose-dependent manner at the same time. CLE and CFE also prevented the depletion of cytosolic antioxidant glutathione (GSH) in RBC. These results suggest that the leaves and flowers of C. japonicum var. ussuriense may have the antioxidant properties.

Antiangiogenic and Antitumor Activities of the Cryptic Fragments with Kringle Architecture

  • Joe, Young-Ae;Kim, Myung-Rae;Shim, Byoung-Shik;Oh, Dae-Shik;Hong, Sung-Hee;Hong, Yong-Kil
    • Biomolecules & Therapeutics
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    • v.11 no.4
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    • pp.205-213
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    • 2003
  • Various angiogenesis inhibitors target vascular endothelial cells and block tumor angiogenesis. Angiostatin is a specific endogenous angiogenesis inhibitor in clinical trials, which contains only the first four triple loop structures, known as kringle domains. Its generated by proteolytic cleavage of its parent molecule plasminogen, which itself does not exhibit antiangiogenic activity. Kringle domains from prothrombin, apolipoprotein, hepatocyte growth factor, urokinase and tissue-type plasminogen activator also elicit anti-angiogenic or antitumor activities in several model systems, albeit low amino acid sequence identity between angiostatin and each individual kringle. However, the differential effects of each kringle domain on endothelial cell proliferation, and migration observed in these kringle domains, suggest that the amino acid sequence of the primary structure is still important although kringle architecture is essential for anti-mlgiogenic activity. If it is further studied as to how amino acid sequence and kringle architecture contributes in anti-angiogenic activity, with studies on underlying mechanisms of anti-angiogenesis by kringle-based angiogenesis inhibitors, it will provide basis for the development of new potent anti-angiogenesis inhibitors and improvement of the efficacy of angiogenesis inhibitors.

Photoprotective Effect of Bamboo (Phyllostachys nigra var. henenis Strapf) Leaf Extract against Ultraviolet Radiation-induced Chronic Skin Damage in the Hairless Mouse (자외선 조사 마우스에서 만성 피부손상에 대한 분죽(Phyllostachys nigra var. henenis Strapf)잎 추출물의 효과)

  • Byeon, Jeong-Soo;Lee, Hae-June;Moon, Changjong;Kim, Jong Choon;Jo, Sung Kee;Jang, Jong Sik;Kim, Tae Hwan;Kim, Sung-Ho
    • Journal of Radiation Industry
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    • v.5 no.3
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    • pp.203-210
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    • 2011
  • To evaluate the ability of Bamboo (Phyllostachys nigra var. henenis Strapf) leaf extract (BL) to protect the skin from photodamage, the gross and microscopic changes in the skin of hairless mice and BL-treated mice exposed chronically to ultraviolet (UV) were examined. The skin of the UV-irradiated mice showed characteristic signs of photoaging, such as deep wrinkles across the back, increased epidermal thickeness, numerous cell infiltration, and many enlarged keratinizing cysts. BL-treated mice showed a significantly decreased wrinkling score and lack of proliferation of cysts. By the 22nd week, 88.9% (i.p. with saline) or 60.0% (topical administration with cream base) of the UV-irradiated mice developed at least one tumor. BL delayed tumor onset significantly. BL (i.p.) was also effective in reducing the occurrence of UV radiation-induced skin tumors and reduced the number of tumors per mouse. After 22 weeks of treatment, 37.5% (i.p.) of the mice treated with BL were tumor-free. Tumor multiplicity was reduced by 81.2% (i.p.) in the BL treated groups. It is noted that skin that is chronically exposed to UV is subject to photoaging and photocarcinogenesis and regular use of BL would prevent these photodamaging effects of UV.

Improvement Effect of Corn Silk, Perilla Leaf and Grape Stem Extract Mixture against UVB-Induced Skin Damage and Compound 48/80-Induced Pruritus (옥수수수염, 들깻잎 및 포도줄기 복합추출물의 UVB 조사 피부 손상 및 Compound 48/80 유도 가려움증 개선 효과)

  • Cho, Byoung Ok;Shin, Jae Young;Che, Denis Nchang;Hwang, Young Min;Lee, Hyun Seo;Ryu, Cheol;Choi, Jiwon;Jang, Seon Il
    • Journal of Radiation Industry
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    • v.10 no.4
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    • pp.231-242
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    • 2016
  • This study was conducted to evaluate the synergistic protective effects of mixtures of corn silk, perilla leaf and grape stem extract (CPG mixture) against UVB-induced skin damage and compound 48/80-induced pruritus in mice. The results showed that treatment with CPG mixture exhibited much stronger suppressive effect on erythema and melanin index as well as melanin formation than treatment with ascorbic acid (AA) in UVB-irradiated mice. Moreover, the treatment with CPG mixture showed ameliorative effect on immune cell infiltration and collagen fiber destruction in UV-irradiated mice. The treatment with CPG mixture inhibited glutathione (GSH) depletion, lipid peroxidation and production of pro-inflammatory cytokines in UVB-irradiated mice. Furthermore, the treatment with CPG mixture inhibited compound 48/80-induced scratching behavior and histological changes in mice. Taken together, these results indicated that CPG mixture has potentials as functional and therapeutic materials against skin damage and itch-related skin diseases.

Selection of Male-sterile and Dwarfism Genetically Modified Zoysia japonica through Gamma Irradiation (감마선 처리에 의한 웅성불임 및 왜성형질의 유전자변형 들잔디(Zoysia japonica Steud.) 선발)

  • Bae, Tae-Woong;Song, In-Ja;Kang, Hong-Gyu;Jeong, Ok-Cheol;Sun, Hyeon-Jin;Ko, Suk-Min;Lim, Pyung-Ok;Song, Pill-Soon;Song, Sung Jun;Lee, Hyo-Yeon
    • Journal of Radiation Industry
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    • v.4 no.3
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    • pp.239-246
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    • 2010
  • The aim of this study is selection of the male-sterile plant for inhibiting transgene flow through gamma-irradiation ($^{60}Co$) at the pollination and fertilization cycle of herbicide-tolerant genetically modified (GM) zoysiagrass (Zoysia japonica Steud.). High frequencies of plant mutations were obtained about 18% from $M_1$ generation at the doses (10 to 50 Gy). We also found that some $M_1$ plants showed male-sterile plants using de-husked seeds and comparison of stainable pollen using $KI-I_2$ solution. Besides the effects of irradiation on pollination and fertilization cycle, various other mutations like dwarf, cold tolerance, increasing grains and mass were observed. Four of dwarfism plants were selected through comparison of morphological characteristic between control and mutants during 4 years. These results demonstrated that the gamma-irradiation on pollination and fertilization cycle is very effective to induce the various mutations, and the male-sterile mutants are useful for controlling transgene flow and developing of high quality turfgasses.

POWER UPRATES IN NUCLEAR POWER PLANTS: INTERNATIONAL EXPERIENCES AND APPROACHES FOR IMPLEMENTATION

  • Kang, Ki-Sig
    • Nuclear Engineering and Technology
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    • v.40 no.4
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    • pp.255-268
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    • 2008
  • The greater demand for electricity and the available capacity within safety margins in some operating NPPs are prompting nuclear utilities to request license modification to enable operation at a higher power level, beyond their original license provisions. Such plant modifications require an in-depth safety analysis to evaluate the possible safety impact. The analysis must consider the thermo hydraulic, radiological and structural aspects, and the plant behavior, while taking into account the capability of the structures, systems and components, and the reactor protection and safeguard systems set points. The purpose of this paper is to introduce international experiences and approaches for implementation of power uprates related to the reactor thermal power of nuclear power plants. The paper is intended to give the reader a general overview of the major processes, work products, issues, challenges, events, and experiences in the power uprates program. The process of increasing the licensed power level of a nuclear power plants is called a power uprate. One way of increasing the thermal output from a reactor is to increase the amount of fissile material in use. It is also possible to increase the core power by increasing the performance of the high power bundles. Safety margins can be maintained by either using fuels with a higher performance, or through the use of improved methods of analysis to demonstrate that the required margins are retained even at the higher power levels. The paper will review all types of power uprates, from small to large, and across various reactor types, including light and heavy water, pressurized, and boiling water reactors. Generally, however, the content of the report focuses on power uprates of the stretch and extended type. The International Atomic Energy Agency (IAEA) is developing a technical guideline on power uprates and side effects of power uprates in nuclear power plants.

Drug induced Pulmonary Edema (약물 유발성폐부종)

  • Sung, Si-Han;Jang, Hye-Young;Lim, Hoon
    • Journal of The Korean Society of Clinical Toxicology
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    • v.8 no.2
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    • pp.113-121
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    • 2010
  • Purpose: Drug-induced non-cardiogenic pulmonary edema has been reported on in a drug case series. For most of the agents that cause pulmonary edema, the pathogenic mechanisms that are responsible for the pulmonary edema remain unknown. We report here on the cases of suspected drug-induced pulmonary edema and we analyze the clinical characteristics. Methods: We reviewed the medical records of 1,345 patients who had drug adverse effects and drug poisoning from January 2005 to July 2010, and 480 of these patients were admitted to the EM Department. Among them, 17 patients developed abnormal chest radiological findings and they were analyzed for any clinical characteristics, the initial symptoms, securing the airway and the clinical results. Results: Seventeen patients out of 480 (3.54%) developed drug-induced abnormal chest radiographic pulmonary edema; they displayed initial symptoms that included mental change (41.2%), dyspnea (17.6%), vomiting (11.8%), etc, and some displayed no symptoms at all (11.8%). Only 3 patients out of the 11 who died or had severe pulmonary edema were able to obtain an advanced airway prior to their arrival to the EM Department. Clinical recovery was generally rapid and this was mostly completed within 6 hours. The mortality rate was 11.8% (2 of 17 patients), and the causative drugs were found to be propofol (35.3%, 6 of 17 patients), multiple drugs (41.2% or 7 out of 17) and one patient each with ephedrine, ethylene glycol, doxylamine and an unknown drug, respectively. Conclusion: Drug-induced pulmonary edema and deaths are not uncommon, and recovery is typically rapid with few long-term sequelae when drug administration is discontinued. Oxygen therapy and securing the airway must be performed during transportation for patients with pulmonary edema.

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A Study on the Analysis of Radiation Dose for Thermoplastic Material and 3D Print Filament Materials (열가소성 플라스틱 재질과 3D 프린트 필라멘트 재질에 대한 방사선량 분석에 관한 연구)

  • Lee, Dong-Yeon
    • Journal of the Korean Society of Radiology
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    • v.15 no.2
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    • pp.181-189
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    • 2021
  • This study is a prior research to manufacture a thermoplastic mask, which is a fixture used in radiation therapy, by 3D printing. It proceeded to analyze the filament material that can replace the thermoplastic. Among the commercially available filament materials, a material having similar characteristics to that of a thermoplastic mask was selected and the radiation dose was compared and analyzed. The experiment used Monte Carlo simulation. The shape in which the mask fixed the head was simulated for the ICRU sphere. The photon fluence was calculated at the skin Hp (0.07), the lens Hp (3), and the whole body Hp (10) by applying a thermoplastic plastic material and a filament material. As a result, when looking at the relative dose based on the thermoplastic plastic material, the difference was approximated within 4%. The material showing the most similar dose was PA-nylon. In selecting an appropriate filament material, it should be selected by comprehensively considering various conditions such as economical efficiency and radiation effects. It is thought that the results of this study can be used as basic data.