• Title/Summary/Keyword: light yield

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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.

Upgrade of Neutron Energy Spectrometer with Single Multilayer Bonner Sphere Using Onion-like Structure

  • Mizukoshi, Tomoaki;Watanabe, Kenichi;Yamazaki, Atsushi;Uritan, Akira;Iguchi, Tetsuo;Ogata, Tomohiro;Muramatsu, Takashi
    • Journal of Radiation Protection and Research
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    • v.41 no.3
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    • pp.185-190
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    • 2016
  • Background: In order to measure neutron energy spectra, the conventional Bonner Sphere Spectrometers (BSS) are widely used. In this spectrometer, several measurements with different size Bonner spheres are required. Operators should, therefore, place these spheres in several times to a measurement point where radiation dose might be relatively high. In order to reduce this effort, novel neutron energy spectrometer using an onion-like single Bonner sphere was proposed in our group. This Bonner sphere has multiple sensitive spherical shell layers in the single sphere. In this spectrometer, a band-shaped thermal neutron detection medium, which consists of a LiF-ZnS mixed powder scintillator sheet and a wavelength-shifting (WLS) fiber readout, was looped to each sphere at equal angular intervals. Amount of LiF neutron converter is reduced near polar region, where the band-shaped detectors are concentrated, in order to uniform the directional sensitivity. The LiF-ZnS mixed powder has an advantage of extremely high light yield. However, since it is opaque, scintillation photons cannot be collect uniformly. This type of detector shows no characteristic shape in the pulse height spectrum. Subsequently, it is difficult to set the pulse height discrimination level. This issue causes sensitivity fluctuation due to gain instability of photodetectors and/or electric modules. Materials and Methods: In order to solve this problem, we propose to replace the LiF-ZnS mixed powder into a flexible and Transparent RUbber SheeT type $LiCaAlF_6$ (TRUST LiCAF) scintillator. TRUST LiCAF scintillator can show a peak shape corresponding to neutron absorption events in the pulse height spectrum. Results and Discussion: We fabricated the prototype detector with five sensitive layers using TRUST LiCAF scintillator and conducted basic experiments to evaluate the directional uniformity of the sensitivity. Conclusion: The fabricated detector shows excellent directional uniformity of the neutron sensitivity.

Plant Growth Promoting Activities of Some Rhizosphere Bacteria and their Effect on Brassica rapa Growth

  • Hussein, Khalid A.;Jung, Yeong Sang;Joo, Jin Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.3
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    • pp.141-146
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    • 2014
  • The necessity to develop economical and eco-friendly technologies is steadily increasing. Plant growth promoting rhizomicrobial strains PGPR are a group of microorganisms that actively colonize plant roots and increase plant growth and yield. Pot experiments were used to investigate the potential of some rhizobacterial strains to enhance the Brassica rapa growth. Microbial strains were successfully isolated from the rhizosphere of Panax ginseng and characterized based on its morphological and plant growth promotion characters. Surface disinfected seeds of Wisconsin Fast B. rapa were inoculated with the selected PGPR microorganisms. The different pots treatments were inoculated by its corresponding PGPR ($10^7cfu\;mL^{-1}$) and incubated in the growth chamber at $25^{\circ}C$ and 65% RH, the light period was adjusted to 24 hours (day). NPK chemical fertilizer and trade product (EMRO, USA) of effective microorganisms as well as un-inoculated control were used for comparison. Plants harvested in 40 days were found to have significant increase in leaf chlorophyll units and plant height and also in dry weight of root and shoot in the inoculated seedlings. Root and shoot length and also leaf surface area significantly were increased by bacterial inoculation in sterile soil. The study suggests that Rhodobacter capsulatus and Azotobacter chroococcum are beneficial for B. rapa growth as they enhance growth and induced IAA production and phosphorus solubilization. This study presents some rhizomicrobial strains that significantly promoted growth of Wisconsin Fast Plant B. rapa in pot experiment under different soil conditions.

The Micrometeorological Requirements for the Culture of Ginseng (Panax sp.) (인삼 (Panax sp.) 재배를 위한 미세기상조건)

  • Proctor John T. A.
    • Proceedings of the Ginseng society Conference
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    • 1988.08a
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    • pp.129-132
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    • 1988
  • Ginseng is cultivated in Korea. Japan. China. the Soviet Union and North America. Studies of the macroclimate of each of these producing areas shows that ginseng has certain requirements for production. In each producing area the microclimate is modified in different ways. Comparisons of recent research data from North America. Korea and China is presented in order to define. more precisely. the various microclimate requirements for ginseng production. These include studies of light interception as influenced by different shade materials. In North America. wood. woven black polypropylene and knitted polyethylene shade are used. whereas in China. dried grasses are bound together in layers with wire and polyvinylchloride is inserted between the layers. The influence of these various shade materials in terms of crop grow1h and root yield are presented. The major effect of temperature seems to be on root growth. During much of the growing season optimum temperatures for root grow1h are not reached. Growth analysis data for different age plants are being used to show the effects of different soil temperature regimes on distribution of dry matter between the shoot and root.

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Effect of Adjuvants on Antibody Titer of Synthetic Recombinant Light Chain of Botulinum Neurotoxin Type B and its Diagnostic Potential for Botulism

  • Jain, Swati;Ponmariappan, S.;Kumar, Om;Singh, Lokendra
    • Journal of Microbiology and Biotechnology
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    • v.21 no.7
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    • pp.719-727
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    • 2011
  • Botulism is a neuroparalytic disease caused by Clostridium botulinum, which produces seven (A-G) antigenically diverse neurotoxins (BoNTs). BoNTs are the most poisonous substances known to humans, with a median lethal dose ($LD_{50}$) of approximately 1 ng/kg of body weight. Owing to their extreme potency and lethality, they have the potential to be used as a bioterrorism agent. The mouse bioassay is the gold standard for the detection of botulinum neurotoxins; however, it requires at least 3-4 days for completion. Attempts have been made to develop an ELISA-based detection system, which is potentially an easier and more rapid method of botulinum neurotoxin detection. The present study was designed using a synthetic gene approach. The synthetic gene encoding the catalytic domain of BoNT serotype B from amino acids 1-450 was constructed with PCR overlapping primers (BoNT/B LC), cloned in a pQE30 UA vector, and expressed in an E. coli M15 host system. Recombinant protein production was optimized at 0.5 mM IPTG final concentration, 4 h post induction, resulting in a maximum yield of recombinant proteins. The immunogenic nature of the recombinant BoNT/B LC protein was evaluated by ELISA. Antibodies were raised in BALB/c mice using various adjuvants. A significant rise in antibody titer (p<0.05) was observed in the Alum group, followed by the Titermax Classic group, Freund's adjuvant, and the Titermax Gold group. These developed high-titer antibodies may prove useful for the detection of botulinum neurotoxins in food and clinical samples.

Wastewater from Instant Noodle Factory as the Whole Nutrients Source for the Microalga Scenedesmus sp. Cultivation

  • Whangchenchom, Worawit;Chiemchaisri, Wilai;Tapaneeyaworawong, Paveena;Powtongsook, Sorawit
    • Environmental Engineering Research
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    • v.19 no.3
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    • pp.283-287
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    • 2014
  • Cultivation of microalgae using wastewater exhibits several advantages such as nutrient removal and the production of high valuable products such as lipid and pigments. With this study, two types of wastewater from instant noodle factory; mixed liquor suspended solids (MLSS) and effluents after sedimentation tank were investigated for green microalga Scenedesmus sp. cultivation under laboratory condition. Optimal wastewater dilution percentage was evaluated in 24 wells microplate. MLSS and effluent without dilution showed the highest specific growth rate (${\mu}$) of $1.63{\pm}0.11day^{-1}$ and $1.57{\pm}0.16day^{-1}$, respectively, in which they were significantly (p < 0.05) higher than Scenedesmus sp. grown in BG11 medium ($1.08{\pm}0.14day^{-1}$). Ten days experiment was also conducted using 2000 ml Duran bottle as culture vessel under continuous light at approximately 5000 lux intensity and continuous aeration. It was found that maximum biomass density of microalgae cultivated in MLSS and effluent were $344.16{\pm}105.60mg/L$ and $512.89{\pm}86.93mg/L$ respectively and there was no significant (p < 0.05) difference on growth to control (BG11 medium). Moreover, cultivation microalgae in wastewater could reduce COD in wastewater by 39.89%-73.37%. Therefore, cultivation of Scenedesmus sp. in wastewater from instant noodle factory can yield microalgae biomass production and wastewater reclamation using photobioreactor simultaneously.

In vitro plantlet regeneration of "dwarf" Indian olive (Elaeocarpus robustus Roxb.): a fruit plant of Bangladesh

  • Rahman, Md. Mahabubur;Amin, Muhammad Nurul;Ishiguri, Futoshi;Yokota, Shinso;Sultana, Rubaiyat Sharmin;Takashima, Yuya;Iizuka, Kazuya;Yoshizawa, Nobuo
    • Plant Biotechnology Reports
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    • v.3 no.3
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    • pp.259-266
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    • 2009
  • A plantlet regeneration protocol was developed on pot-grown mature plants of Elaeocarpus robustus Roxb. cv. Dwarf from nodal and leaf explants. The best yield of adventitious shoots was achieved from the leaf-derived calli in a modified MS ($MMS_1$, half strength of major salts, full strength of minor salts, and vitamins) medium containing $4.0{\mu}M$ BA + $4.0{\mu}M$ Kn + $0.5{\mu}M$ NAA + 15% coconut water (CW). The shoot multiplication rate was amplified about twofold per culture after the addition of 15% CW to the medium. The rate of shoot multiplication reached maximum at the 5th subculture, and it maintained this rate throughout the 3 subsequent subcultures. The best rooting in vitro was investigated by subculturing the microcuttings in an $MMS_2$ (half strength of both major salts and minor salts and full strength of vitamins) medium containing $1.0{\mu}M$ IBA in the dark for one initial week at $30^{\circ}C$, followed by subculturing them in a plant-growth regulator (PGR)-free medium in the light. The plantlets raised in vitro were successfully established under ex vitro conditions.

Dynamics of Microalgae Along the Coastal Areas of Sooyoung Bay, Busan, South Korea

  • Prasad, Binod;Thiyam, General;Lee, Dong-Gyu;Kim, Moo-Sang;Cho, Man-Gi
    • Journal of Marine Bioscience and Biotechnology
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    • v.5 no.4
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    • pp.40-45
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    • 2011
  • Microalgae are one of the major, sustaining components of ecosystem processes and are responsible for biogeochemical reactions that drive our climate changes. Despite this, many marine microalgae are poorly described and little is known of their abundance and distribution along the coastal areas of Sooyoung Bay, Busan, South Korea. The present study has been conducted from November, 2011 to August, 2009 with the objective to provide an overview of the taxonomy diversity and abundance of microalgae along the coastal areas of the Sooyoung Bay. Water samples were collected from different sites, which were located by using a GPS tracker. Chlorophyll fluorescence of the water samples were measured by using ToxY-PAM dual-channel yield analyzer. The chlorophyll fluorescence values were relatively higher during the spring and summer and even in the region near to the sea port. Similarly the abundance of microalgae was higher near the port but diversity index had lower values. The temperature and pH values were same at all the sites. However, only the temperature varied during the sampling period, with higher values during summer and lower in winter. From the preliminary results, the following class of microalgae were found; Bacillariophyceae, Dinophyceae, Silicoflagellate and Cryptophyceae. With a future ongoing work, microalgae are being isolated to establish single cell culture and for identification using light microscopic observations, photography and molecular approaches.

Salt-induced Differential Gene Expression in Italian Ryegrass (Lolium multiflorum Lam.) Revealed by Annealing Control Primer Based GeneFishing approach

  • Lee, Ki-Won;Lee, Sang-Hoon;Choi, Gi Jun;Ji, Hee Jung;Hwang, Tae Young;Kim, Won Ho;Rahman, Md. Atikur
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.37 no.3
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    • pp.231-236
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    • 2017
  • Salt stress is one of the most limiting factors that reduce plant growth, development and yield. However, identification of salt-inducible genes is an initial step for understanding the adaptive response of plants to salt stress. In this study, we used an annealing control primer (ACP) based GeneFishing technique to identify differentially expressed genes (DEGs) in Italian ryegrass seedlings under salt stress. Ten-day-old seedlings were exposed to 100 mM NaCl for 6 h. Using 60 ACPs, a total 8 up-regulated genes were identified and sequenced. We identified several promising genes encoding alpha-glactosidase b, light harvesting chlorophyll a/b binding protein, metallothionein-like protein 3B-like, translation factor SUI, translation initiation factor eIF1, glyceraldehyde-3-phosphate dehydrogenase 2 and elongation factor 1-alpha. These genes were mostly involved in plant development, signaling, ROS detoxification and salt acclimation. However, this study provides new molecular information of several genes to understand the salt stress response. These genes would be useful for the enhancement of salt stress tolerance in plants.

Comparison of Chlorophyll Fluorescence of Three Citrus Rootstocks and Satsuma Mandarin Grafted on Them (감귤 대목과 그것에 접목한 온주밀감의 엽록소 형광특성의 비교)

  • Han, Sang Heon
    • Horticultural Science & Technology
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    • v.19 no.2
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    • pp.149-152
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    • 2001
  • Leaf chlorophyll fluorescence capable to estimate $CO_2$ assimilation was compared among three citrus rookstocks: trifoliate orange (Poncitrus trifoliate L.), 'Flying Dragon' (Poncitrus trifoliate L. var. monstrosa) and citromelo (Poncitrus trifoliate L.${\times}$Citrus paradisi), as well as among satsuma mandarin (Citrus unshiu cv. Nichinan No.1) grafted on the 3 rootstocks. Citromelo, the most vigorous rootstock; and 'trifoliate orange'; the most common cultivar and moderate rootstocks gave the same potential and actual quantum yields, whereas 'Flying Dragon' (very dwarf) had lower values due to a higher Fo and Fs for fluorescence obtained from dark-adapted and light-adapted leaves, respectively. These findings show that the absorbed photon energy was dissipated more as fluorescence from the antena chlorophyll in 'Flying Dragon' than trifoliate orange or 'swingle' citrimelo. The satsuma mandarins grafted on these rootstocks did not, however, show the differences observed in the rootstocks by having all the same potential and actual quantum yields. It is suggested that the rootsocks do not potentially or actually electron transport in the Photosystem II (PS II) of satsuma mandarin grafted on the 3 rootstocks.

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