• Title/Summary/Keyword: Py

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Membrane-Ordering Effects of Barbiturates on Pure Phospholipid Model Membranes

  • Knag, Jung-Sook;Chung, Young-Za;Cho, Goon-Jae;Byun, Won-Tan;Yun, Il
    • Archives of Pharmacal Research
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    • v.15 no.3
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    • pp.196-203
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    • 1992
  • Intramolecular excimer formation of 1, 3-di(1-pyrenyl)propane (Py-3-Py) and fluorescence polarization of 1, 6-diphenyl-1, 3, 5-hexatriene (DPH) were used to investigate the effects of barbiturates on the fluidity of model membranes of phosphatidycholine (SPMVPC), phosphatidylserine (SPMVPS), and phosphatidylinositol (SPMVPI) fractions of synaptosomal plasma membrane vesicles (SPMV) isolated from bovine cerebral cortex. In a dose-dependent manner, barbiturates decreased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py and increased the anisotropy(r), rotational relaxation time (P), limiting anisotropy $(r_infty)$, and order parameter (S) of DPH in SPMVPC, SPMVPS and SPMVPI. This indicates that barbiturates decreased both the lateral and rotational diffusion of the probes in SPMVPC, SPMVPS and SPMVPI. The relative potencies of barbiturates in ordering the membranes were in the order: pentobarbital > hexobarbital > amobarbital > phenobarbital. This order correlates well with the anesthetic potencies of barbiturates and the potencies for enhancement of $\gamma$-aminobutyric acid-stimulated chloride uptake. Thus, it is strongly suggested that a close relationship might exist between the membrane ordering effects of barbiturates and the chloride fluxes across SPMV.

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Infection and cox2 sequence of Pythium chondricola (Oomycetes) causing red rot disease in Pyropia yezoensis (Rhodophyta) in Korea

  • Lee, Soon Jeong;Jee, Bo Young;Son, Maeng-Hyun;Lee, Sang-Rae
    • ALGAE
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    • v.32 no.2
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    • pp.155-160
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    • 2017
  • Red rot disease has caused a major decline in Pyropia (Nori) crop production in Korea, Japan, and China. To date, only Pythium porphyrae (Pythiales, Oomycetes) has been reported as the pathogen causing red rot disease in Pyropia yezoensis (Rhodophyta, Bangiales). Recently, Pythium chondricola was isolated from the infected blades of Py. yezoensis during molecular analyses using the mitochondrial cox1 region. In this study, we evaluated the pathogenicity of P. chondricola as an algal pathogen of Py. yezoensis. Moreover, a new cox2 marker was developed with high specificity for Pythium species. Subsequent to re-inoculation, P. chondricola successfully infected Py. yezoensis blades, with the infected regions containing symptoms of red rot disease. A novel cox2 marker successfully isolated the cox2 region of Pythium species from the infected blades of Py. yezoensis collected from Pyropia aquaculture farms. cox2 sequences showed 100% identity with that of P. chondricola (KJ595354) and 98% similarity with that of P. porphyrae (KJ595377). The results of the pathogenicity test and molecular analysis confirm that P. chondricola is a new algal pathogen causing red rot disease in Pyropia species. Moreover, it could also suggest the presence of cryptic biodiversity among Korean Pythium species.

A Study on the Change of Unit Floor Plan of Apartment House in Korea-Focused on Interior Image Preference using Computer Simulation- (아파트 단위 평면 변화과정에 관한 연구-안방 및 거실 중심으로-)

  • 김경순
    • Korean Institute of Interior Design Journal
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    • no.12
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    • pp.50-56
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    • 1997
  • In the past thirty years, apartment house has been greatly developed and the housing supply has improved some degree. However, the fact is that interior space planning of apartment house still has a lot of problems. The purpose of this study is to research the change of interior room. The 160 examples of unit floor plan(40-85m2 i.e. 12.1py-25.7py) were selected and classified according to master bedroom type and living room area when was constructed by the city of Seoul and KNHC from 1970 to 1990. And then, the change of each area, size and ratio were analyzed and researched. The result of this research can be summarized as follows: 1. Size of unit floor plan was on the increase from 16.02py to 17.86py. 2. 2 bedroom type, master bedroom showed a rise of size and occupancy ratio. Living room grew larger than 1982-1991 for size and occupancy ratio. 3. 3 bedroom type, master bedroom was increased in size and occupancy ratio was reduced to 19.99%. Size of living room became broader than master bedroom and occupancy ratio(1972-1981) increased over 1982-1991. Through this analysis and research, this study is to provide the basic data for actural design process and to suggest future trend of apartment house.

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A novel red light-emitting material and the characteristics of OLEDs using the same as red dopant

  • Lim, Seung-Han;Park, Jung-Hyun;Seo, Ji-Hoon;Ryu, Gweon-Young;Kim, Young-Kwan;Shin, Dong-Myung
    • 한국정보디스플레이학회:학술대회논문집
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    • 2007.08b
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    • pp.1573-1576
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    • 2007
  • ABCV-Py, a new red fluorescent material, in which two identical electron donor (dimethylamino group) and acceptor (cyano group) moieties are linked to two independent biphenyl groups which share the same core phenyl, has been synthesized for use in OLED application. Performance of red doped electroluminescent devices using ABCV-Py as dopant were measured with various host materials, $Alq_3$, CBP, DPVBi, and p-terphenyl. The performance of device with DPVBi host material was better than those with other host materials and high doping concentration could be applied on device with ABCV-Py as dopant.

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Effects of Parathyroid Hormone on the Fluidity of the Plasma Membrane Vesicles of Cultured Osteoblasts

  • Kang, Jung-Sook
    • Journal of Photoscience
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    • v.8 no.3_4
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    • pp.87-92
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    • 2001
  • Intramolecular excimer formation of 1,3-di(1-pyrenyl)propane (Py-3-Py) and fluorescence polarization of 1,6-diphenyl-1,3,5-hexatriene (DPH) were used to investigate the effects of parathyroid hormone (PTH) on the bulk bilayer fluidity of the plasma membrane vesicles isolated from cultured osteoblasts (OB-PMV). In a dose-dependent manner, rat PTH-(1-34) [rPTH-(1-34)] increased the excimer to monomer fluorescence intensity ratio (I'/I) of Py-3-Py and decreased the anisotropy (r) of DPH in OB-PMV. This indicates that PTH increased both the lateral and rotational diffusion of the probes in OB-PMY. Selective quenching of DPH fluorescence by trinitrophenyl groups was utilized to examine the transbilayer fluidity asymmetry of OB-PMV. The anisotropy, limiting anisotropy, and order parameter of DPH in the inner monolayer were 0.024, 0.032, and 0.062 greater than calculated for the outer monolayer of OB-PMY. Selective quenching of DPH fluorescence by trinitrophenyl groups was also utilized to examine the transbilayer effects of PTH on the fluidity of OB-PMV. rPTH-(1-34) had a greater fluidizing effect on the outer monolayer as compared to the inner monolayer of OB-PMV. Thus, it has been proven that PTH exhibits a selective rather than nonselective fluidizing effect within transbilayer domains of OB-PMV.

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Simultaneous degradation of nitrogenous heterocyclic compounds by catalytic wet-peroxidation process using box-behnken design

  • Gosu, Vijayalakshmi;Arora, Shivali;Subbaramaiah, Verraboina
    • Environmental Engineering Research
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    • v.25 no.4
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    • pp.488-497
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    • 2020
  • The present study investigates the feasibility of nitrogenous heterocyclic compounds (NHCs) (Pyridine-Quinoline) degradation by catalytic wet peroxidation (CWPO) in the presence of nanoscale zerovalent iron supported on granular activated carbon (nFe0/GAC) using statistical optimization technique. Response surface methodology (RSM) in combination with Box-Behnken design (BBD) was used to optimize the process parameters of CWPO process such as initial pH, catalyst dose, hydrogen peroxide dose, initial concentration of pyridine (Py) and quinolone (Qn) were chosen as the main variables, and total organic carbon (TOC) removal and total Fe leaching were selected as the investigated response. The optimization of process parameters by desirability function showed the ~85% of TOC removal with process condition of initial solution pH 3.5, catalyst dose of 0.55 g/L, hydrogen peroxide concentration of 0.34 mmol, initial concentration of Py 200 mg/L and initial concentration of Qn 200 mg/L. Further, for TOC removal the analysis of variance results of the RSM revealed that all parameter i.e. initial pH, catalyst dose, hydrogen peroxide dose, initial concentration of Py and initial concentration of Qn were highly significant according to the p values (p < 0.05). The quadratic model was found to be the best fit for experimental data. The present study revealed that BBD was reliable and effective for the determination of the optimum conditions for CWPO of NHCs (Py-Qn).

Identification of Marker Compounds for Discriminating between Embryogenic and Nonembryogenic Calluses of Higher Plants Using Pyrolysis Gas Chromatography Mass Spectrometry and Genetic Programming

  • Kim Suk-Weon;Ban Sung-Hee;Yoo Ook-Joon;Liu Jang-Ryol
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.1
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    • pp.38-42
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    • 2006
  • When whole cells are subjected to pyrolysis gas chromatography/mass spectrometry (Py-GC/MS) analysis, it provides biochemical profiles containing overlapping signals of the majority of compounds. To determine marker compounds that discriminate embryogenic calluses from nonembryogenic calluses, samples of embryogenic and nonembryogenic calluses of five higher plant species were subjected to Py-GC/MS. Genetic programming of Py-GC/MS data was able to discriminate embryogenic calluses from nonembryogenic calluses. The content ratio of 5-meyhyl-2-furancarboxaldehyde and 5-(hydroxymethyl)-2-furancarboxaldehyde was greater in nonembryogenic calluses than in embryogenic calluses. However, the content ratio of phenol, p-cresol, and $^1H-indole$ in embryogenic calluses was 1.2 to 2.4 times greater than the ratio in nonembryogenic calluses. These pyrolysates seem to be derived from the components of the cell walls, which suggests that differences in cell wall components or changes in the architecture of the cell wall playa crucial role in determining the embryogenic competence of calluses.

Fabrication of SiCf/SiC Composites using an Electrophoretic Deposition

  • Lee, Jong-Hyun;Gil, Gun-Young;Yoon, Dang-Hyok
    • Journal of the Korean Ceramic Society
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    • v.46 no.5
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    • pp.447-451
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    • 2009
  • Continuous SiC fiber-reinforced SiC composites ($SiC_f$/SiC) were fabricated by electrophoretic deposition (EPD). Nine types of slurries with different powder contents, binder resin amounts and slurry pH were deposited on Tyranno$^{TM}$-SA fabrics by EPD at 135 V for ten minutes to determine the optimal conditions. Further EPD using the optimum slurry conditions was performed on fabrics with four different pyrolitic carbon (PyC) thicknesses. The density of the hot-pressed composites decreased with increasing PyC thickness due to the difficulty of infiltrating the slurry into the narrow gaps between the fibers. On the other hand, the mechanical strength increased with increasing PyC thickness despite the decrease in density, which was explained by the enhanced crack deflection with increasing PyC thickness. The $SiC_f$/SiC composites showed the highest density and flexural strength of 94% and 342 MPa, respectively, showing EPD as a feasible method for dense $SiC_f$/SiC fabrication.

Improvement of Substrate and Insulationg Layer of FM Magnetic Tunneling Jundtion and the Study of Magnetic Transport (기판과 부도체층을 개선한 $FM/Al_2O_3/FM$ (FM=Ferromagnet) 자기터널링 접합제작 및 자기수송에 관한 연구)

  • 변상진;박병기;장인우;염민수;이재형;이긍원
    • Journal of the Korean Magnetics Society
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    • v.9 no.5
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    • pp.245-250
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    • 1999
  • The effect of substrate and oxidization time on $substrate /Py/Al_2O_3/Co\;(Py=Ni_{81}Fe_{19})$ tunnel junction was studied. Samples were prepared without breaking vacuum by changing shadow masks in-situ. The resistance of tunnel junctions increased, but measured MR decreased with oxidization time. Negative MR observed for samples of tunnel resistivity lower than 0.17 M$\Omega$ $({\mu}m)^2$. MR resistivity decreased with the change of substrates in the order of thermally oxidized Si(111), Si(100), Coring Glass 2948, Corning Glass 7059. Sign change and the variation of MR was explained with non uniform current effect.

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Stress Analysis for Fiber Reinforced Composites under Indentation Contact Loading (압입접촉하중이 작용하는 섬유강화 복합재료의 응력해석)

  • Jang, Kyung-Soon;Kim, Tae-Woo;Kim, Chul;Woo, Sang-Kuk;Lee, Kee-Sung
    • Journal of the Korean Ceramic Society
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    • v.45 no.4
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    • pp.238-244
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    • 2008
  • Modeling and FEM analysis on Boron Nitride and/or Pyrolytic Carbon coating layers on SiC fibers under indentation contact loadings are investigated. Especially this study attempts to model the mechanical behavior of the SiC fibers with and without coatings. Tyranno S grade and Tyranno LoxM grade of SiC are selected for fiber and Boron Nitride and/or Pyrolytic Carbon as coating material. The modeling is performed by SiC fiber without coating layer, which includs single(BN or PyC) and double(BN-PyC or PyC-BN) coating layer. And then the analysis is performed by changing a type of coating layer, a type of fiber and coating sequence. In this study, the concepts of modeling and analysis techniques for optimum design of BN and PyC coating process on SiC fiber are shown. Results show that stresses are reduced when indentation contact loading applies on the material having lower elastic modulus.