• Title/Summary/Keyword: light activation

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Reevaluation of Photon Activation Yields of 11C, 13N, and 15O for the Estimation of Activity in Gas and Water Induced by the Operation of Electron Accelerators for Medical Use

  • Masumoto, Kazuyoshi;Matsumura, Hiroshi;Kosako, Kazuaki;Bessho, Kotaro;Toyoda, Akihiro
    • Journal of Radiation Protection and Research
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    • v.41 no.3
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    • pp.286-290
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    • 2016
  • Background: Activation of air and water in the electron linear accelerator for medical use has not been considered severely. By the new Japanese regulation for protection of radiation hazard, it became indispensable to evaluate of activation of air and water in the accelerator room. The measurement of induced activity in air and water components in the electron energy region of 10 to 20 MeV is very difficult, because this energy region is close to the threshold energy region of photonuclear reactions. Then, we measured the photonuclear reaction yields of $^{13}N$, $^{15}O$, and $^{11}C$ by using the electron linear accelerator. Obtained data were compared with the data calculated by the Monte Carlo method. Materials and Methods: An activation experiment was performed at the Research Center for Electron Photon Science, Tohoku University. Highly purified $SiO_2$, $Si_3N_4$, and carbon disks were irradiated for 10 minutes by bremsstrahlung converted by a tungsten plate. Induced activity from C, N, and O was obtained. Monte Carlo calculation was performed using MCNP5 and AERY (DCHAIN-SP) to simulate the experimental condition. Cross section data were adopted the KAERI dataset. Results and Discussion: In our experiment in hospital, calculated values were not agreed with experimental values. It might be three possible reasons as the cause of this deference, such as irradiation energy, calculation procedure and cross section data. Obtained data of this work, calculated and experimental values were good agreement with each other within one order. In this work, we used KAERI dataset of photonuclear reaction instead of JENDL. Therefore, it was found that the photonuclear cross section data of light elements are most important for yield calculation in these reactions. Conclusion: Further improvement for calculation using a new dataset JENDL/PD-2015 and considering electron energy spreading will be needed.

Effect of sweet potato purple acid phosphatase on Pseudomonas aeruginosa flagellin-mediated inflammatory response in A549 cells

  • Heyeon, Baik;Jaiesoon, Cho
    • Animal Bioscience
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    • v.36 no.2
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    • pp.315-321
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    • 2023
  • Objective: The study was conducted to investigate the dephosphorylation of Pseudomonas aeruginosa flagellin (PA FLA) by sweet potato purple acid phosphatase (PAP) and the effect of the enzyme on the flagellin-mediated inflammatory response in the A549 lung epithelial cell line. Methods: The activity of sweet potato PAP on PA FLA was assayed at different pH (4, 5.5, 7, and 7.5) and temperature (25℃, 37℃, and 55℃) conditions. The release of interleukin-8 (IL-8) and the activation of nuclear factor kappa- light-chain-enhancer of activated B cells (NF-κB) in A549 cells exposed to PA FLA treated with or without sweet potato PAP was measured using IL-8 and NF-κB ELISA kits, respectively. The activation of toll-like receptor 5 (TLR5) in TLR5-overexpressing HEK-293 cells exposed to PA FLA treated with or without sweet potato PAP was determined by the secreted alkaline phosphatase-based assay. Results: The dephosphorylation of PA FLA by sweet potato PAP was favorable at pH 4 and 5.5 and highest at 55℃. PA-FLA treated with the enzyme decreased IL-8 release from A549 cells to about 3.5-fold compared to intact PA FLA at 1,000 ng/mL of substrate. Moreover, PA-FLA dephosphorylated by the enzyme repressed the activation of NF-κB in the cells compared to intact PA FLA. The activation of TLR5 by PA-FLA was highest in TLR-overexpressing HEK293 cells at a substrate concentration of 5,000 ng/mL, whereas PA FLA treated with the enzyme strongly repressed the activation of TLR5. Conclusion: Sweet potato PAP has the potential to be a new alternative agent against the increased antibiotic resistance of P. aeruginosa and may be a new conceptual feed additive to control unwanted inflammatory responses caused by bacterial infections in animal husbandry.

A Study on the Safety Management and Activation of Construction Remodeling (건축물 리모델링의 활성화 및 안전관리방안에 관한 연구)

  • 양극영;김천학;윤여완
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2002.05a
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    • pp.103-108
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    • 2002
  • The purposes of this research are to use the buildings efficiently and long, save energies, make the cozy and comfortable environment of residential and living spaces, rearrange the related acts for easy implementation of remodelling, and activate the government's support programs so as to make remodelling activated in a safe mode. The scope and methodology of this research include the review of existing literatures and data on remodelling, census on apartment residents, influence factors, and the development of methods for activation of building remodelling and strengthening of safety management, like activation measures, licensing and ordering regulation updates, etc regarding the remodelling. Safety inspection and in-depth inspection before and after remodelling should be regulated. The construction materials for remodelling should be light weighted and the construction methods which can minimize the impact and vibration during construction should be selected. The improvement of regulation on the remodelling contractor qualification and order method should be updated. If the remodelling is activated and safety management is reinforced by the suggested measures, solving of lack of house, prevention of abuse of resources, and improvement of residential environment could be accomplished rationally.

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A Study on the Activation and Safety Management of Construction Remodeling (건축물 리모델링의 활성화 및 안전관리방안에 관한 연구)

  • Yang, Keek-Young;Kim, Chun-Hag;Yoon, Yer-Wan
    • Journal of the Korea Institute of Building Construction
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    • v.2 no.2
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    • pp.134-143
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    • 2002
  • The purposes of this research are to use the buildings efficiently and long, save energies, make the cozy and comfortable environment of residential and living spaces, rearrange the related acts for easy implementation of remodeling, and activate the government's support programs so as to make remodeling activated in a safe mode. The scope and methodology of this research include the review of existing literatures and data on remodeling, census on apartment residents, influence factors, and the development of methods for activation of building remodeling and strengthening of safety management, like activation measures, licensing and ordering regulation updates, etc regarding the remodeling. Safety inspection and in-depth inspection before and after remodeling should be regulated. The construction materials for remodeling should be light weighted and the construction methods which can minimize the impact and vibration during construction should be selected. The improvement of regulation on the remodeling contractor qualification and order method should be updated. If the remodeling is activated and safety management is reinforced by the suggested measures, solving of lack of house, prevention of abuse of resources, and improvement of residential environment could be accomplished rationally.

A Study on the High Temperature Deformation Behavior of a Solid Solution Aluminium Alloy (알루미늄 고용체 합금의 고온변형 거동에 관한 연구)

  • Kim, Ho-Gyeong
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.21 no.2
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    • pp.346-351
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    • 1997
  • The creep characteristics of an Al-5wt.% Ag alloy including the stress exponent, the activation energy for creep and the shape of the creep curve were investigated at a normalized shear stress extending from $ 10^{-5}{\;}to{\;}3{\times}10^{-4}$ and in the temperature range of 640-873 K, where silver is in solid solution. The experimental results shows that the stress exponent is 4.6, the activation energy is 141 kJ/mole, and the stacking fault energy is $180{\;}mJ/m^2$, suggesting that the creep behavior of Al-5 wt.% Ag is similiar to that reported for pure aluminum, and that under the current experimental conditions, the alloy behaves as a class II(metal class). The above creep characteristics obtained for Al-5 wt.% Ag are discussed in the light of prediction regarding deformation mechanisms in solid solution alloys.

A Study on the Safety Management and Activation of Construction Remodeling (건축물 리모델링의 활성화 및 안전관리방안에 관한 연구)

  • Yang, Keek-Young;Kim, Chun-Hag
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.6 no.2
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    • pp.233-244
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    • 2002
  • The purposes of this research are to use the buildings efficiently and long, save energies, make the cozy and comfortable environment of residential and living spaces, rearrange the related acts for easy implementation of remodeling, and activate the government's support programs so as to make remodeling activated in a safe mode. The scope and methodology of this research include the review of existing literatures and data on remodeling, census on apartment residents, influence factors, and the development of methods for activation of building remodeling and strengthening of safety management, like activation measures, licensing and ordering regulation updates, etc regarding the remodeling. Safety inspection and in-depth inspection before and after remodeling should be regulated. The construction materials for remodeling should be light weighted and the construction methods which can minimize the impact and vibration during construction should be selected. The improvement of regulation on the remodeling contractor qualification and order method should be updated. If the remodeling is activated and safety management is reinforced by the suggested measures, solving of lack of house, prevention of abuse of resources, and improvement of residential environment could be accomplished rationally.

Efficiency of Phototransduction Cascade in Carp Cones

  • Tachibanaki, Shuji;Tsushima, Sawae;Kawamura, Satoru
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.44-46
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    • 2002
  • In the vertebrate retina, rods mediate twilight vision and cones daylight vision. Rods have been purified easily from the retina, and thus the phototransduction mechanism in rods is now well documented. However, it has not been possible to purify cones in large quantities, and therefore, the knowledge on the mechanism in cones is limited. Here we report purification of carp (Cyprinus carpio) cones with a stepwise Percoll gradient. Using purified cells, we compared the phototransduction mechanism between rods and cones. The results showed that both transducin activation and phosphodiesterase activation are less effective, and visual pigment phosphorylation is faster in cones. These differences explain lower light-sensitivity and briefer photoresponse time course in cones.

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Measurements of Thermal Neutron Spectrum Parameters in the TRIGA Mark II Reactor

  • Yang, Jae-Choon
    • Nuclear Engineering and Technology
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    • v.11 no.1
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    • pp.21-27
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    • 1979
  • The relative reaction rates were measured in the TRIGA Mark II reactor core and analyzed to obtain the neutron spectrum parameters; relative neutron temperature T$^{n}$ and epithermal index (equation omitted) Measurements were made with the central thimble and the F2 position containing the light water. The relative neutron temperature was represented by the activation ratio of Lu-Mn, and the epithermal index was measured by Au-Mn foil activation. The multichannel analyzer was used to measure the relative ${\gamma}$-rays of the detector foils. The results were compared with the calculated values.

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Glia as a Link between Neuroinflammation and Neuropathic Pain

  • Jha, Mithilesh Kumar;Jeon, Sang-Min;Suk, Kyoung-Ho
    • IMMUNE NETWORK
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    • v.12 no.2
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    • pp.41-47
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    • 2012
  • Contemporary studies illustrate that peripheral injuries activate glial components of the peripheral and central cellular circuitry. The subsequent release of glial stressors or activating signals contributes to neuropathic pain and neuroinflammation. Recent studies document the importance of glia in the development and persistence of neuropathic pain and neuroinflammation as a connecting link, thereby focusing attention on the glial pathology as the general underlying factor in essentially all age-related neurodegenerative diseases. There is wide agreement that excessive glial activation is a key process in nervous system disorders involving the release of strong pro-inflammatory cytokines, which can trigger worsening of multiple disease states. This review will briefly discuss the recent findings that have shed light on the molecular and cellular mechanisms of glia as a connecting link between neuropathic pain and neuroinflammation.

Creep Behaviours of Glasses Rim Material Alloy (안경테소재 합금(Ti-6AI-4V)의 크리프 특성)

  • 황경충;윤종호
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.10a
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    • pp.248-253
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    • 2003
  • Titanium alloy has widely been used as glasses rim material because it has high specific strength and also is light, harmless to men. But, we have little design data about the creep behaviors of the alloy. Therefore, in this study, an apparatus has been designed and built for conducting creep tests under constant load conditions. A series of creep tests on them have been performed to get the basic design data and life prediction of titanium products and we have gotten the following results. First, the stress exponents decrease as the test temperatures increase. Secondly, the creep activation energy gradually decreases as the stresses become bigger. Thirdly, the constant of Larson-Miller parameters on this alloy is estimated about 13. And last, the fractographs at the creep rupture show both the ductile and the brittle fracture according to the creep conditions.

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