• Title/Summary/Keyword: Gamma source

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Diversity and Characterization of Endophytic Bacteria Associated with Tidal Flat Plants and their Antagonistic Effects on Oomycetous Plant Pathogens

  • Bibi, Fehmida;Yasir, Muhammad;Song, Geun-Cheol;Lee, Sang-Yeol;Chung, Young-Ryun
    • The Plant Pathology Journal
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    • v.28 no.1
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    • pp.20-31
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    • 2012
  • Endophytic bacterial communities of tidal flat plants antagonistic to oomycete plant pathogens were studied by the isolation of 256 root colonizing endophytic bacteria from surface-disinfected root tissues of six plants ($Rosa$ $rugosa$, $Suaeda$ $maritima$, $Vitex$ $rotundifolia$, $Carex$ $scabrifolia$, $Glehnia$ $littoralis$ and $Elymus$ $mollis$) growing in a tidal flat area of Namhae Island, Korea. To understand the antagonistic potential, an $in$ $vitro$ antagonistic assay was performed to characterize and identify strains that were antagonistic to the oomycete plant pathogens $Phytophthora$ $capsici$ and $Pythium$ $ultimum$ from the total population. Nine percent of the total number of isolated bacteria exhibited in vitro inhibitory activity against target plant pathogenic oomycetes. Taxonomic and phylogenetic placement of the antagonistic bacteria was investigated by analysis of the 16S rRNA gene sequences. The sequence analysis classified the antagonistic strains into four major classes of the domain bacteria ($Firmicutes$, ${\alpha}-Proteobacteria$, ${\gamma}-Proteobacteria$ and $Actinomycetes$) and 10 different genera. Further production of secondary metabolites, hydrolytic enzymes and plant growth promoting traits were determined for the putative new species of antagonistic endophytic bacteria. These new strains could not be identified as known species of ${\alpha}-Proteobacteria$, and so may represent novel bacterial taxa. The unexpected high antagonistic bacterial diversity associated with the tidal flat plants may be indicative of their importance in tidal flat plants as a promising source of novel antimicrobial compounds and biocontrol agents.

Development of Prototype Electronic Dosimeter using the Silicon PIN Diode Detector (실리콘 PIN 다이오드 검출기를 이용한 전자선량계 개발)

  • Lee, B.J.;Kim, B.H.;Chang, S.Y.;Kim, J.S.
    • Journal of Radiation Protection and Research
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    • v.25 no.4
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    • pp.197-205
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    • 2000
  • A prototype electronic dosimeter(PED) adopting a silicon PIN diode detector as a radiation detector has been developed, manufactured and test-evaluated. A radiation signal processing circuit has been electronically tested and then the radiation detection characteristics of this PED has been performance-tested by using a reference photon radiation field. As a result in a electronic performance test, radiation signals from a detector were well observed in the signal processing circuit. The radiation detection sensitivity of this PED after several test-irradiations to $^{137}Cs$ gamma radiation source appeared to be 1.85 cps/$Gy{\cdot}h^{-1}$ with 19.3% of the coefficient of variation, which satisfied the performance criteria for the active personnel radiation monitor. Further improvement of the electronic circuit and operating program will enable the PED to be used in personal monitoring purpose.

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Enhancement of Proliferation and Antigen Presentation of Human B Cells in Vitro by K562 Cells Expressing CD40L (CD40L 발현 K562 세포주를 이용한 시험관내 B 세포 증식과 항원제공능 증가)

  • Park, Jung-Yong;Yoon, Sung-Hee;Kim, Eun-Kyung;Yun, Sun-Ok;Sohn, Hyun-Jung;Kim, Tai-Gyu
    • IMMUNE NETWORK
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    • v.7 no.2
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    • pp.80-86
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    • 2007
  • Background: CD40-activated B (CD40-B) cells might be an attractive source of autologous antigen-presenting cells (APCs) for immunotherapy due to the convenience to obtain from peripheral blood and expand in vitro. Moreover, CD40-B cells were found to be comparable with DCs in their capacity to raise antigen-specific CD8+ T cells. Here, we have established K562 cells expressing CD40L to expand CD40-activated B cells used for APCs. Methods: After activation of B cell by K562/CD40L, CD40-B cells were examined by counting B cell numbers. Surface expression of CD54, CD80, CD86 and HLA class II was measured by flow cytometry. The CD40-B cells were tested for its function as APC by mixed lymphocyte reactions (MLR) and by induction of T cell responses specific for pp65 peptide in vitro. Results: The expansion of B cells by K562/CD40L increased about 6-folds compared with anti-CD40 or K562. Furthermore, the expression of CD54, CD80, CD86 and HLA class II was up-regulated by K562/CD40L. B cells by K562/CD40L showed comparable antigen presentation activity with mature DCs as shown in MLR, INF-${\gamma}$ ELISPOT assay. Conclusion: These results suggest that K562/CD40L could be used to generate activated B cells as potent APCs which could be useful for cellular vaccination and adoptive immunotherapy.

GC-MS Analysis of Chemical Constituents from Various Agarwood (GC-MS를 이용한 침향류의 성분 비교 연구)

  • Shin, Kwhang-Ho;Choi, Kyu-Yeol;Cho, Sung-Yong;Ahn, Duk-Kyun;Park, Seong-Kyu
    • The Korea Journal of Herbology
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    • v.26 no.1
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    • pp.7-12
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    • 2011
  • Objectives : The purpose of this study is to evaluate the quality of four different kinds of agarwood and analysis chemical constituents by GC-MS. Methods : Four source plants were two of Vietnamese agarwood, Indonesian agarwood and Myanmar agarwood. These plant materials were named sample No. 1-4. The chemical constituents of each agarwood were analysed by GC-MS. Results : GC-MS analysis showed that ${\beta}$-selinene was found in all the samples. The Vietnamese agarwood, Sample 1, and 4 has contained 6.861% and 7.497% of ${\beta}$-selinene and reached the highest level at the retention times 46.245 and 46.274 (min). Sample 2, the Myanmar agarwood has contained 1.608%, the lowest level of ${\beta}$-selinene, and it also has contained about 20% of ${\alpha}-,{\beta}-,{\gamma}$-eudesmol and 4.076% of valerianol. Sample 3, the Indonesian agarwood has contained 9.59% of ${\beta}$-selinene, 9.493% of ${\beta}$-selinene and shown its highest level (more than 19%) at the retention time 43.998 (min). Conclusion : It suggested that ${\beta}$-selinene could be a standard marker to evaluate agarwood by GC-MS analysis.

Photocurrent Properties and Growth of $CuAlSe_2$ Single Crystal Thin Film by Hot Wall Epitaxy (Hot Wall Epitaxy(HWE)법에 의한 $v_2$ 단결정 박막의 성장과 광전류 특성)

  • You, Sang-Ha;Hong, Kwang-Joon
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2003.07a
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    • pp.282-285
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    • 2003
  • Single crystal $CuAlSe_2$ layers were grown on thoroughly etched semi-insulating GaAs(100) substrate at $410\;^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating $CuAlSe_2$ source at $680\;^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of single crystal $CuAlSe_2$ thin films measured with Hall effect by van der Pauw method are $9.24{\times}10^{16}\;cm^{-3}\;and\;295\;cm^2/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $CuAlSe_2$ obtained from the absorption spectra was well described by the Varshni's relation, $E_g(T)\;=\;2.8382\;eV\;-\;(8.68\;{\times}\;10^{-4}eV/K)T^2/(T\;+\;155\;K)$. The crystal field and the spin-orbit splitting energies for the valence band of the $CuAlSe_2$ have been estimated to be 0.2026 eV and 0.2165 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the $\Delta$so definitely exists in the ${\Gamma}_5$ states of the valence band of the $CuAlSe_2$. The three photocurrent peaks observed at 10 K are ascribed to the $A_1-$, $B_1-$, and $C_1$-exciton peaks for n = 1.

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A Study on the Effects of Electroencephalogram of Blocking Electromagnetic Wave Materials by useing the Nano Silver (나노 은을 이용한 전자파 차폐 직물이 뇌파에 미치는 영향)

  • Lee, Su-Jeong;Lee, Tae-Il
    • Fashion & Textile Research Journal
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    • v.6 no.6
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    • pp.810-814
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    • 2004
  • This study is one of the fundamental researches for the development of future smart clothing and textile products using silver(Ag) nano powder. Our study was focused on the blocking or insulating effects of nano-processed textiles from electromagnetic waves. Also, for the surveying of the actual effect to human body, we measure the variation of electroencephalogram which is an indication of human physical symptoms. Among various textiles in this experiment, nano silver processed case has shown the best blocking performance from the electromagnetic waves, which decreases depending on the distance. As a reference model of working environment, we setup the visual stimuli object on the computer that is a source of electromagnetic wave. The power spectrum distribution and the incidence of electroencephalogram was measured. The analysed data has shown that, with nano-processed textiles, ${\beta}$ wave does not appear very often where ${\beta}$ wave appears only to illustrate the stable states of human's body. However, as for the materials without nano processing, the ratio of ${\gamma}$ waves in the total level of electroencephalogram becomes higher in spite of short exposure to visual stimuli in work environment, which shows that the worker becomes stressed. The ${\beta}$ wave electroencephalogram of all materials is drawn in calcarine fissure of occipital lobe to show the convergent distribution, and stronger with block-processed Nano Silver Silk(NSS). The study based on the potential risks of human diseases such as physical fatigue by electromagnetic waves, and has shown that the application of Nano Silver textile for human uses require a proper particle size of it which would not penetrate cellular tissues, and a proper binder and binding treatment for it. However, it is highly required for back-up researches to verify various aspects in applying nano silver to textile products.

Fermentation Increases Antidiabetic Effects of Acanthopanax Senticosusbhpark@chonbuk.ac.kr (발효에 의한 오가피의 항당뇨 활성 촉진)

  • Ham, Seong-Ho;Lim, Byung-Lak;Yu, Jia-hua;Ka, Sun-O;Park, Byung-Hyun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.22 no.2
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    • pp.340-345
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    • 2008
  • Extract of Acanthopanax senticosus has recently been demonstrated to possess significant antidiabetic potential, in accordance with the traditional use of this plant as an antidiabetic natural health product. The present study evaluated the effects of fermented extract (FE) of this plant on glucose-stimulated insulin secretion, glucose uptake, and streptozotocin-induced type 1 diabetes model. A 3 h pretreatment with FE prevented $IL-1{\beta}$ and $IFN-{\gamma}$ toxicity in isolated rat islets. However, it did not affect insulin-stimulated glucose uptake in C2C12 myotubes. In addition, pretreatment of mice with FE blocked the destruction of streptozotocin-induced islets and the development of type 1 diabetes. FE reduced blood glucose level, increased insulin secretion, and improved glucose tolerance in streptozotocin-treated mice, whereas nonfermented extract (NFE) had moderate effects. Immunohistochemical staining for insulin clearly showed that pretreatment with FE blocked the STZ-induced islets destruction and restored the number of islet cells that secreted insulin to the level of the control. Although the active principles and their mechanisms of action remain to be identified, FE may nevertheless represent a novel complementary therapy and a source of novel therapeutic agents against type 1 diabetes mellitus.

Antioxidant activity and polyphenol content of fermented Sparassis latifolia extracts (꽃송이버섯 발효물의 항산화 활성 및 폴리페놀 함량 변화)

  • Yang, Seung-Hwa;Lee, Yong-Jo;Kim, Da-Song;Shin, Hyun-Jae
    • Journal of Mushroom
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    • v.17 no.4
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    • pp.268-274
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    • 2019
  • Sparassis latifolia is a useful medicinal mushroom that has recently gained popularity in Asia. It has a rich flavor and is a good source of nutrients contains a large number of polyphenols for a functional food or dietary supplement. In addition, S. latifolia is rich in beta-glucan and gamma-aminobutyric acid (GABA). These two compounds have been reported to show immune-stimulating and anticancer effects by numerous studies. In this study, four species of lactic acid bacteria (Lactobacillus plantarum subsp. plantarum, L. acidophilus, L. helveticus, and L. delbrueckii subsp. bulgaricus) were used to ferment the fruiting body of S. latifolia. Fermented S. latifolia extracts were found to have a higher polyphenol content and antioxidant activity following fermentation as well as increased protease activity.

Growth and study on photocurrent of valence band splitting for AgGaSe2 single crystal thin film by hot wall epitaxy (Hot Wall Epitaxy(HWE)법에 의한 AgGaSe2 단결정 박막 성장과 가전자대 갈라짐에 대한 광전류 연구)

  • Lee, Gyoan-Gyu;Hong, Kwang-Joon
    • Journal of Sensor Science and Technology
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    • v.15 no.6
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    • pp.397-405
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    • 2006
  • Single crystal $AgGaSe_{2}$ layers were grown on thoroughly etched semi-insulating GaAs(100) substrate at $420^{\circ}C$ with hot wall epitaxy (HWE) system by evaporating $AgGaSe_{2}$ source at $630^{\circ}C$. The crystalline structure of the single crystal thin films was investigated by the photoluminescence and double crystal X-ray diffraction (DCXD). The carrier density and mobility of single crystal $AgGaSe_{2}$ thin films measured with Hall effect by van der Pauw method are $4.05{\times}10^{16}/cm^{3}$, $139cm^{2}/V{\cdot}s$ at 293 K, respectively. The temperature dependence of the energy band gap of the $AgGaSe_{2}$ obtained from the absorption spectra was well described by the Varshni's relation, $E_{g}(T)$=1.9501 eV-($8.79{\times}10^{-4}{\;}eV/K)T^{2}$/(T+250 K). The crystal field and the spin-orbit splitting energies for the valence band of the $AgGaSe_{2}$ have been estimated to be 0.3132 eV and 0.3725 eV at 10 K, respectively, by means of the photocurrent spectra and the Hopfield quasicubic model. These results indicate that the splitting of the ${\Delta}So$ definitely exists in the ${\Gamma}_{5}$ states of the valence band of the $AgGaSe_{2}$. The three photocurrent peaks observed at 10 K are ascribed to the $A_{1}-$, $B_{1}-$, and $C_{1}-$exciton peaks for n=1.

Fatty Acid Composition and Volatile Constituents of Protaetia brevitarsis Larvae

  • Yeo, Hyelim;Youn, Kumju;Kim, Minji;Yun, Eun-Young;Hwang, Jae-Sam;Jeong, Woo-Sik;Jun, Mira
    • Preventive Nutrition and Food Science
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    • v.18 no.2
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    • pp.150-156
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    • 2013
  • A total of 48 different volatile oils were identified form P. brevitarsis larvae by gas chromatography/mass spectrometry (GC/MS). Acids (48.67%) were detected as the major group in P. brevitarsis larvae comprising the largest proportion of the volatile compounds, followed by esters (19.84%), hydrocarbons (18.90%), alcohols (8.37%), miscellaneous (1.71%), aldehydes (1.35%) and terpenes (1.16%). The major volatile constituents were 9-hexadecenoic acid (16.75%), 6-octadecenoic acid (14.88%) and n-hexadecanoic acid (11.06%). The composition of fatty acid was also determined by GC analysis and 16 fatty acids were identified. The predominant fatty acids were oleic acid ($C_{18:1}$, 64.24%) followed by palmitic acid ($C_{16:0}$, 15.89%), palmitoleic acid ($C_{16:1}$, 10.43%) and linoleic acid ($C_{18:2}$, 4.69%) constituting more than 95% of total fatty acids. The distinguished characteristic of the fatty acid profile of P. brevitarsis larvae was the high proportion of unsaturated fatty acid (80.54% of total fatty acids) versus saturated fatty acids (19.46% of total fatty acids). Furthermore, small but significant amounts of linoleic, linolenic and ${\gamma}$-linolenic acids bestow P. brevitarsis larvae with considerable nutritional value. The novel findings of the present study provide a scientific basis for the comprehensive utilization of the insect as a nutritionally promising food source and a possibility for more effective utilization.