• Title/Summary/Keyword: AtPR4

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Studies on a PR4 Gene for Breeding Disease Resistant Forage Crops (내병성 목초 품종개량을 위한 PR4 유전자의 연구)

  • Cha, Joon-Yung;Ermawati, Netty;Jung, Min-Hee;Kim, Ki-Yong;Son, Dae-Young
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.27 no.4
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    • pp.241-248
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    • 2007
  • Cytokinins are essential plant hormones that play crucial roles in various aspects of plant growth and development. By using mRNA differential display, we isolated a cytokinine-inducible cDNA encoding pathogenesis-related (PR) 4 from Arabidopsis amp1 mutant. The full-length PR4 cDNA, designated AtPR4, contains an open reading frame of 212 amino acids with calculated molecular mass of 22,900 Da and isoelectric point (pI) of 7.89. Genomic DNA blotting showed that the Arabidopsis genome has one copy of AtPR4. AtPR4 mRNA was induced by cytokinin and NaCl, but decreased by SA or JA treatment. PR proteins are induced in response to pathogen attack. Thus the AtPR4 gene isolated in this study may be a useful candidate for genetic engineering of forage crops for increased tolerance against pathogen.

Magnetic properties of $(Nd_{1-x}R_x)_2Fe_{14}B$ (R=Y, Pr) ($(Nd_{1-x}R_x)_2Fe_{14}B$ (R=Y, Pr)의 자기특성)

  • 김만중;김윤배;김희태;김택기
    • Journal of the Korean Magnetics Society
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    • v.8 no.5
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    • pp.271-274
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    • 1998
  • Spin reorientation and magnetocrystalline anisotropy of magnetically aligned $(Nd_{1-x}R_x)_2Fe_{14}B$ (R=Y, Pr) power were studied. The spin reorientation temperature $(T_{SR})$ of $(Nd_{1-x}R_x)_2Fe_{14}B$ decreases linearly by increasing Pr-substitution with the ratio of ${\Delta}T_{SR}=-1.35$ K/Pr at.% in composition range of 0$\leq$x$\leq$0.75. The spin reorientation temperature of $(Nd_{1-x}R_x)_2Fe_{14}B$ decreases by increasing Pr-substitution to 118 K (x=0.5) then increases to 122 K (x=0.75). The spin reorientation angle at 4.2 K decreases by increasing rare earth substitution with the ratio of $\Delta$SRA=-0.073$^{\circ}$/Y at.% and $\Delta$SRA=-0.258$^{\circ}$/Pr at.% in composition range of 0$\leq$x$\leq$0.5. The spin reorientation is expected to disappear at x$\geq$0.9 in case of $(Nd_{1-x}R_x)_2Fe_{14}B$ and at x$\geq$0.8 in case of $(Nd_{1-x}R_x)_2Fe_{14}B$.

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Studies on the Bacteriophages of Brevibacterium lactofermentum (L-글루타민산 생산균 Brevibacterium lactofermentum의 Bacteriophag에 관한 연구)

  • 이태우
    • Korean Journal of Microbiology
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    • v.17 no.3
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    • pp.97-130
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    • 1979
  • Many industrial processes those employ bacteria are subjected to phage infestations. In L-glutamic acid fermentions using acetic acid, the phage infestations of the organisms have been recently recognized. In efforts to elucidate the sources of phage contamination involved in the abnormal fermentation, a series of study was conducted to isolate the phages both from the contents of abnormally fermented tanks and the soil or sewage samples from the surroundings of a fermentation factory, to define major charateristics of the phage isolates, and finally to determine the correlation between the phage isolates and temperate phages originating from the miscellaneous bacterial species isolated from the soil or sewage samples. The results are summarized as follows; 1) All phages were isolated from the irregular fermentation tanks and soil or sewage samples, and they were designated as phage PR-1, PR-2, PR-3, PR-4, PR-5, PR-6, and PR-7, in the order of isolation. These PR-series phages were proved to be highly specific for the variant strains of Br. lactofermentum only, namely, phage PR-1 and PR-2 for Br. lactofermentum No. 468-5 and phage PR-3~PR-7 for Br. lactofemrentum No. 2256. By cross-neutralization test, the 7 phagescould be subdivided into 3 groups, i. e., phage PR-I and PR-2 the first, phage PR-3, PR-4, PR-5, PR-6 the second, and the phage PR-7 the third. 2) The 7 phages were virulent under the experimental conditions. They produced plaques with clear and relatively sharp margins without distinct halo. The mean sizes of plaques were 1.5mm in diameter for phage PR-1 and PR-2, and 1. Omm for phages PR-3~PR-7. Double layer technique modified by Hongo and described by Adams, was applied to assay of the PR-series phages. The factors influencing the plaques were as follows;young age cells of host bacteria cultured for 3-6 hours represented the largest number and size, optimum was pH 7.0, incubation temperature was $30^{\circ}C$, and agar concentration and amount of overlayer medium were 0.6% and 0.2ml, respectively. 3) PR-series phages were stable in 0.05M tris buffer and 0.1M ammonium acetate buffer solution. The addition of $5{\times}10^{-3}M$ magnesium ion effectively increased the stability. Thermostability experiments indicated that PR-series phages were stable at the teinperture between $50^{\circ}{\sim}55^{\circ}C$ in nutrient medium, $45^{\circ}{\sim}50^{\circ}C$ in buffer solution. However, the phages mere completely inactivated at 603C and 65$^{\circ}$C within 10 minutes. The phages were stable at the range of pH6~9 in nutrient medium and of pH 8-9 in buffer solution, respectively. Exposure of the phages to UV for 25, 60 and 100 seconds resulted in the complete loss of infectivily, respectively. 4) Electron microscopy showed that PR-series phage particles exhibited rather similar morphology, differing in the size All of PR-series phages had a multilateral head and had a simple long tiil about three to five times long as compared with head. By the size, phage PR-1 and PR-2, PR-3, PR-4, PR-5, and PR-6 and PR-7 were classified into same groups, respectively. The head and tail size of phage PR-1, PR-5, PR-5(T) and PR-7 were 85nm, 74nm and 235nm and 350mm, and 72nm and 210nm, respectively. 5) Nucleic acids of PR-series phages were double stranded DNA. The G+C contents of phage PR-1, PR-5 and PR-7 were 56.1, 52.9 and 53.7, respectively. The values of G+C contents derived from the $T_m$ were in agreement with the chemically determined values. 6) PR-series phages effectively adsorbed on their host bacteria at the rate of more than 90% during 5 min. K value for phage PR-1, PR-5 and PR-7 were calculated to be $6{\times}10^9 ml$ per minute, respectiveky. The pH of the medium did effect adsorption rate, but both temperature and age of host cells did not. Generally, optimum adsorption condition of phages seemed to be almost same as optimum growth conditions of host bacteria. 7) In one-step growth experiments, the latent periods at $30^{\circ}C$ for PR-1, and PR-7 were about 70, 50 and 55 min, respectively. The corresponding average burst size was 200, 70 and 90, respectively. Lpsis period according to the multiplicity of infection and a phage series. In case of m. o. i. 100, strain No. 2256 (PR-5) and No. 468-5(PR-1) failed to grow and turbidity decreased after 50 and 70min, respectively. 8) In the lysate of a plaque purified phage PR-5 infected bacteria, there observed 2 types ofphage particles, i. e., phage PR-5 and PR-5 (T) of similar morphology but differing at the length of phage tail, and phage tail like particles. The phage taillike particles could be divided into 4 types by the length. Induction experiments of Br. lactofermentum with UV irradiation, mitomycin C or bacitracin treatment produced neither phage PR-5 (T) or phage tail-like particles. 9) No lysis occured when the growth of 7 strains of miscellaneous bacteria, isolated from soil and sewage samples, were inoculated with either phage PR-5 (T) or phage tail-like particles the inoculation of phage PR-5 pellet resulted in the growth inhibition of the orgainsms in the spot test. The lysates obtained from 3 miscellaneous soil derived bacteria following mitomycin C treatment the growth of Br. lactofermentum, but did not lyze the bacterium.

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A PRML System for Perpendicular Magnetic Recording Channel in Wireless Multimedia Networks (무선 멀티미디어 네트워크에서 수직 자기기록장치를 위한 PRML 시스템)

  • Kim Jeong-so;Hwang Gi-yean
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.5 no.5
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    • pp.454-457
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    • 2004
  • Partial response maximum likelihood (PRML) is a powerful and indispensable detection scheme for perpendicular magnetic recording channels. The proposed method is a low complexity detection scheme which is related to the PRML system. The simulation results show that PR(1,2,3,4,3,2,1)ML and PR(l,2,3,3,2,1)ML using modulation encoding with R=2/3 have the most improved performance at K=3,4. However, in the case of K=3, R=2/3 PR(1,1,1,1)ML effectively reduces the complexity compared to PR(1,2,3,3,2,1), but it has L5dB performance degradation at most. In the case of K=4, R=l PR(1,2,2,1)ML has very low complexity compared to R=2/3 PR(l,2,3,4,3,2,1)ML. but it has about 2dB performance degradation at most.

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A Study on the Luminescent Characteristics of YPO4:Pr3+ Phosphor by the Content Ratio of Pr6O11 and Calcination Temperature (Pr6O11의 함량 및 열처리 조건에 따른 YPO4:Pr3+ 형광체의 발광 특성 연구)

  • Min Jun Kim;Seong Eui Lee
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.37 no.1
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    • pp.68-73
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    • 2024
  • In this study, the praseodymium-doped yttrium phosphate (YPO4:Pr3+) powder, which is well known for its high luminescent efficiency, and long life in the UV range, was synthesized with various content ratios of Pr6O11 and calcination temperature. Crystal structure and luminescent properties of various phosphor powders based on different concentrations and calcination conditions were characterized by XRD (X-Ray Diffraction) and PL (photoluminescence) spectrometers. From the XRD analysis, the structure of YPO4:Pr3+ which is calcinated at 1,200℃ was stable tetragonal phase and crystal size was calculated about 25 nm by Scherrer equation. PL emission of YPO4:Pr3+ with a different content ratio of Pr6O11 by excitation λexc=250 nm shows that 0.75 mol% phosphor powder has maximum PL intensity and PL decreases with the increase of the ratio of Pr6O11 up to 1.25 mol% which is caused by changes of crystallinity of phosphor powders. With increasing dopant ratio, photo-luminescence Emission decreases due to Concentration quenching, which is commonly observed in phosphors. Currently, 0.75 mol% is considered the optimal doping concentration. A hybrid ultraviolet-emitting device incorporating YPO4:Pr3+ fluorescent material with plasma discharge was fabricated to enhance UV germicidal effects while minimizing ozone generation. UV emission from the plasma discharge device was shown at about 200 nm and 350 nm which caused additional emission of the regions of 250 nm, 315 nm, and 370 nm from the YPO4:Pr3+ phosphor.

Studies on Improving the Physical Properties of Pr-Fe-B System Rare-Earth Magnets (Pr-Fe-B계 희토류 자석의 물리적 특성 향상에 관한 연구)

  • 고재귀;임상희
    • Journal of the Korean Magnetics Society
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    • v.6 no.5
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    • pp.305-309
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    • 1996
  • To obtain the Pr-Fe-B ternary system magnets with higher $(BH)_{max}$, the effect of composition ratio and various heat-treatment temperatures on the magnetic properties of Pr-Fe-B system rare-earth magnets were investigated. The magnets with various composition of Pr and Fe were heat-treated at $990^{\circ}C$, $625^{\circ}C$, $585^{\circ}C$, $550^{\circ}C$ after sintering. Curie temperature is $310^{\circ}C$ and quantitative analysis by SEM, EDX shows that the $Pr_{2}Fe_{14}B$, Pr-rich phase consist of Pr~14 at.% and Fe~86 at.%, Pr~58 at.% and Fe~42 at.%, respectively. The coercivity is decreased after heat-treating at $990^{\circ}C$ and increased from 5.6 to 6.3 kOe at $625^{\circ}C$. The maximum energy product is decreased from 43.4 to 30.3 MGOe after the heat-treating at $990^{\circ}C$ but increased from 42.7 to 45.0 MGOe, about 5 %, by heat-treating at $625^{\circ}C$.

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The Experimental Study on the Suppression Effect of Asthma and Immune Response Improvement of Platycodi Radix Herbal-acupuncture (길경약침(桔梗藥鍼)의 천식억제(喘息抑制) 및 면역조절효과(免疫調節效果)에 대(對)한 실험적(實驗的) 연구(硏究))

  • Park, Chi-Young;Kim, Young-Il;Hong, Kwon-Eui
    • Journal of Acupuncture Research
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    • v.22 no.6
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    • pp.61-74
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    • 2005
  • Objectives : The aim of this study was to investigate the effect of Asthma-depression and Immunoregulation with PR-HAS(Herbal-acupuncture with Platycodi Radix infusion solution) injection at Joksamni(St36) on ovalbumin-induced asthma in mice. Methods : C57BL/6 mice were sensitized and challenged with OVA(ovalbumin) for 12 weeks(once a week). The experimental group(OVA-PR-HA) wase treated with concentrations(1%) of PR-HAS at Joksamni(St36) for the later 8 weeks(3times/week). The second experimental group(OVA-Needle prick) was treated with Needle-Prick at Joksamni(St36) for the later 8 weeks(3times/week). Results : 1. The weight and total cells in the mice lung treated with PR-HA decreased significantly compared with that of control group. 2. Total leukocytes and eosinophils in BALF of the mice group treated with PR-HA decreased remarkably compared with those of control group. 3. The sticking of collagen on histological analysis of lung sections, the mice group treated with PR-HA decreased significantly compared with those of control group. 4. The concentrations of IL-4, IL-5, IgE in BALF, and IL-4, IL-5, IL-13 in serum of the mice group treated with PR-HA decreased significantly compared with those of control group. 5. The number of $Gr-1^+/CD11b^+\;and\;CD11b^+$ cells in the lungs of the mice group treated with PR-HA decreased significantly compared with that of control group. 6. The numbers of $CCR3^+\;cells,\;CD4^+\;cells\;and\;CD8^+\;cells$ in the lungs, and $CD3e^+/CD69^+$ in the lungs of the mice group treated with PR-HA decreased significantly compared with those of control group. 7. The mRNA expression of ${\beta}-actin,\;TNF-{\alpha}$, IL-4, IL-5,IL-13 in the mice group treated with PR-HA with RT-PCR decreased significantly compared with those of control group. Conclusion : The concentrations of IL-4, IL-5, IgE in BALF, and IL-4, IL-5, IL-13 in serum of the mice group treated with PR-HA decreased significantly compared with those of control group. The number of $Gr-1^+/CD11b^+\;and\;CD11b^+$ cells in the lungs of the mice group treated with PR-HA decreased significantly compared with that of control group. The numbers of $CCR3^+\;cells,\;CD4^+\;cells\;and\;CD8^+\;cells$ in the lungs, and $CD3e^+/CD69^+$ in the lungs of the mice group treated with PR-HA decreased significantly compared with those of control group. The mRNA expression of ${\beta}-actin,\;TNF-{\alpha}$, IL-4, IL-5, IL-13 in the mice group treated with PR-HA with RT-PCR decreased significantly compared with those of control group. These result suggests that Platycodi Radix Herbal-acupuncture at Joksamni(St36) in C57BL/6mice may be an effictive part to OVA-induced asthma in C57BL/6 mice.

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The Effects of Peucedani Radix Herbal Acupuncture at St36 on Ovalbumin-induced Asthma in C57BL Mouse (전호약침(前胡藥鍼)이 Ovalbumin-induced Asthma Mouse Model에 미치는 영향)

  • Roh, Hong-Pyo;Seol, In-Chan;Kim, Yoon-Sik
    • Journal of Acupuncture Research
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    • v.22 no.6
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    • pp.1-15
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    • 2005
  • Objectives : The aim of this study was to investigate the effect of Peucedani Radix herbal acupuncture(PR-HA) at St36(joksamni) on ovalbumin-induced asthma in mice. Methods : C57BL/6 mice were sensitized and challenged with OVA(ovalbumin) for 12 weeks(once a week) C57BL/6 mice were injected, inhaled and sprayed with OVA for 12 weeks (3times a week). One of the two experimental groups was just treated with needle-prick on St36 and the other group was treated with 1% concentrations of PR-HAS at St36, for the later 8 weeks (3times /week). Results : 1. The weight and total cells of lung of the mice group treated with PR-HA decreased significantly compared with those of control group. 2. Total Leukocytes and Eosinophils in BALF of the mice group treated with PR-HA decreased significantly compared with those of control group. 3. Eosinophils in BALF of the mice group treated with PR-HA in Photomicrographs decreased significantly compared with those of control group. 4. According to Histological analysis of lung sections, it decreased significantly adhension of collagen in PR-HA than those of control group 5. The concentration of IgE, IL-4, IL-5, in BALF and IL-4, IL-5, Il-13 in serum of the mice group treated with PR-HA decreased significantly compared with that of control group. 6. The number of Gr-1+/CD11b+, CD11b+, CD3-/CCR3+, CD4+, CD3e+/CD69+ , CD23+B220+ cells in the lungs of the mice group treated with PR-HA decreased significantly compared with those of control group. 7. The cytokine's manifestation of mRNA of the mice group treated with PR-HA with RT-PCR decreased significantly compared with that of control group. Conclusion : We conclude that PR-HA is effective on OVA-induced asthma of C57BL/6 mouse.

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The Effect of Pr Additive on Magnetostriction of Amorphous Fe-B Alloy (Pr 첨가가 Fe-B 비정질합금의 자왜에 미치는 영향)

  • 조용수;김윤배;김창석;김택기
    • Journal of the Korean Magnetics Society
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    • v.4 no.2
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    • pp.126-129
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    • 1994
  • In order to invetigate the effect of Pr additive on the magnetostriction of amorphous Fe-B alloys, amorphous $Fe_{86-x}B_{14}Pr_{x}(2{\leq}x{\leq}8\;at.%)$ alloys were prepared by a rapid solidification process. As the Pr content increased in the as-prepared amorphous $Fe_{84}B_{14}Pr_{2}$ alloy annealed at $300^{\circ}C$ for 2 hr increased to 70 ppm. Ac power loss and permeability$(f=50\;kHz,\;B_{m}=0.1\;T)$ of the annealed amorphous $Fe_{84}B_{14}Pr_{2}$ alloy were 15 W/kg and $5.5{\times}10^{3}$, respectively.

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Fabrication of UV-C Emitting YPO4:Pr3+ Powder and Properties of YPO4:Pr3+-PVDF Electroluminescence Device (자외선-C 발광 YPO4:Pr3+ 분말제조 및 YPO4:Pr3+-PVDF 전계 발광소자 특성 연구)

  • Baek, GyeongDo;Afandi, Mohammad M.;Park, Jehong;Kim, Jongsu;Jeong, Yongseok
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.2
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    • pp.15-18
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    • 2022
  • The ultraviolet-C emitting praseodymium doped yttrium phosphate (YPO4:Pr3+) powder was synthesized by conventional solid-state reaction. The electroluminescence device was fabricated by simple screen-printing method using the synthesized YPO4:Pr3+ powder, especially, polyvinylidene fluoride as an insulating layer was applied on the printed YPO4:Pr3+ powder for stable performance of the electroluminescence. The electroluminescence properties were investigated under alternating current power system of 400 Hz. The device starts to emit at 350 V, which showed the ultraviolet-C emission peaking at the 233, 245, 264, 273 nm attributed to electronic transition of the Pr3+ ions. The electroluminescence intensity was increased as increasing the operating voltage and the device revealed stable performance up to 600 V due to the polyvinylidene fluoride serve as a protective layer.