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101.
Glutathione reductase was purified from chicken liver and some characteristics of the enzyme were investigated. The purification
procedure was composed of four steps: preparation of homogenate, ammonium sulfate precipitation, 2′,5′-ADP Sepharose 4B affinity
chromatography, and Sephadex G-200 gel filtration chromatography. Owing to the four consecutive procedures, the enzyme was
purified 1714-fold, with a yield of 38%. Specific activity at the final step was 120 enzyme unit (EU)/mg of protein. The purified
enzyme showed a single band on sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weight
of the enzyme was found to be 100 kDa by Sephadex G-200 gel filtration chromatography, and the subunit molecular weight was
found to be 43 kDa by SDS-PAGE. Optimum pH, stable pH, optimum ionic strength, and optimum temperature were 7.0, 7.4, 0.75
M Tris-HCl buffer including 1 mM EDTA, and 50°C, respectively. K
M and V
max values for NADPH and glutathione disulfide (GSSG) substrates were also determined for the enzyme. 相似文献
102.
The oligomer of 4-(4-pyridylmethylideneimino)phenol was formed during oxidative polycondensation in aqueous alkaline medium
using oxygen as the oxidant. Optimum conditions of the oxidative polycondensation and the main parameters of the process were
found. The maximum yield of the oligomer was 52.4%. The product was characterized by elemental analysis, FT-IR spectroscopy,
UV-Vis spectroscopy, and 1H NMR spectroscopy. The molecular weight distribution was determined by size exclusion chromatography. Thermogravimetric and
differential thermal analyses were carried out for 4-(4-pyridylmethylideneimino)phenol and its oligomer.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 1785–1788, October, 2006. 相似文献
103.
Ibrahim Demir Ertugrul Sahmetlioglu Gokcen Y. Celik Murat Unal 《Russian Journal of General Chemistry》2008,78(7):1458-1462
A novel ligand has been synthesized by the condensation of 1,3-diaminoprophane (HL) wıth isonitroso-p-chloroacetophenone. The complexes of cobalt(II), nicel(II), cupper(II) and zinc(II) with HL were prepared. All compounds
were characterized by spectroscopic techniques and its antibacterial activities were determined by the disc diffusion method
used against to those gram-positive and-negative bacteria. All compounds were investigated by cyclic voltammetry at 25°C.
The voltammograms were recorded with a potential scan of 100 mV s−1.
The text was submitted by the authors in English. 相似文献
104.
105.
T. M. Aliev D. A. Demir E. Iltan N. K. Pak 《Zeitschrift fur Physik C Particles and Fields》1995,69(1):481-484
Theg B*B? andg D*D? coupling constants are calculated at the intermediate momentum transfer interval 0.5 GeV2≤Q 2≤1.5 GeV2, in the context of QCD sum rules. Our predictions are in good agreement with those of the Vector Dominance Model 相似文献
106.
Measurement of L X-Ray Intensity Ratios for^92U and ^90Th Elements Using Photoionization in an External Magnetic Field 下载免费PDF全文
D.Demir Y. Sahin 《中国物理快报》2007,24(3):668-671
L x-ray intensity ratios Le/Lγ, Lα/L7 and Lβ/Lγ for ^92U and ^90Th are measured by using 59.5keV incident photon energy at 110° and 125° scattering angles. The samples are located in the external magnetic field of intensities ±0.15T, ±0.30T, ±0.45T, ±0.60T and ±0.75T. The experimental results obtained for B = 0 are compared with the theoretical values calculated using Scofield's tables based on the Hartree Slater theory. The contribution to the alignment of the external magnetic field is discussed. It is observed that the L x-ray intensity ratios decrease with the increasing magnetic field intensity. 相似文献
107.
Sabriye Acikgoz Bukem Bilen Mustafa Muamer Demir Yusuf Ziya Menceloglu Yani Skarlatos Gulen Aktas Mehmet Naci Inci 《Optical Review》2008,15(2):84-90
Humidity induced change in the refractive index and thickness of the polyethylene glycol (PEG) coatings are in situ investigated for a range from 10 to 95%, using an optical waveguide spectroscopic technique. It is experimentally demonstrated
that, upon humidity change, the optical and swelling characteristics of the PEG coatings can be employed to build a plastic
fibre optic humidity sensor. The sensing mechanism is based on the humidity induced change in the refractive index of the
PEG film, which is directly coated onto a polished segment of a plastic optical fibre with dip-coating method. It is observed
that PEG, which is a highly hydrophilic material, shows no monotonic linear response to humidity but gives different characteristics
for various ranges of humidity levels both in index of refraction and in thickness. It undergoes a physical phase change from
a semi-crystalline structure to a gel one at around 80% relative humidity. At this phase change point, a drastic decrease
occurs in the index of refraction as well as a drastic increase in the swelling of the PEG film. In addition, PEG coatings
are hydrogenated in a vacuum chamber. It is observed that the hydrogen has a preventing effect on the humidity induced phase
change in PEG coatings. Finally, the possibility of using PEG coatings in construction of a real plastic fibre optic humidity
sensor is discussed. 相似文献
108.
Bauer F Bisplinghoff J Büsser K Busch M Colberg T Demirörs L Dahl C Eversheim PD Eyser O Felden O Gebel R Greiff J Hinterberger F Jonas E Krause H Lehmann C Lindlein J Maier R Meinerzhagen A Pauly C Prasuhn D Rohdjess H Rosendaal D von Rossen P Schirm N Scobel W Ulbrich K Weise E Wolf T Ziegler R;EDDA Collaboration 《Physical review letters》2003,90(14):142301
At the Cooler Synchrotron COSY/Jülich spin-correlation parameters in elastic proton-proton (pp) scattering have been measured with a 2.11 GeV polarized proton beam and a polarized hydrogen atomic beam target. We report results for A(NN), A(SS), and A(SL) for c.m. scattering angles between 30 degrees and 90 degrees. Our data on A(SS)--the first measurement of this observable above 800 MeV--clearly disagrees with predictions of available pp scattering phase-shift solutions while A(NN) and A(SL) are reproduced reasonably well. We show that in the direct reconstruction of the scattering amplitudes from the body of available pp elastic scattering data at 2.1 GeV the number of possible solutions is considerably reduced. 相似文献
109.
H. Rohdjeß F. Bauer J. Bisplinghoff K. Büßer M. Busch T. Colberg L. Demirörs C. Dahl P. D. Eversheim O. Eyser O. Felden R. Gebel J. Greiff F. Hinterberger E. Jonas H. Krause C. Lehmann J. Lindlein R. Maier A. Meinerzhagen C. Pauly D. Prasuhn D. Rosendaal P. von Rossen N. Schirm W. Scobel K. Ulbrich E. Weise T. Wolf R. Ziegler 《The European Physical Journal A - Hadrons and Nuclei》2003,18(2-3):555-558
At the Cooler-Synchrotron COSY/Jülich polarized and unpolarized elastic proton-proton scattering has been investigated with the EDDA-Experiment in the energy range (
-2.5 GeV). By taking scattering data during the acceleration of the beam with a large-acceptance (
-
) detector, precise excitation functions for differential cross-section and analyzing power have been measured in small energy steps with consistent normalization with respect to luminosity and polarization. These data have helped to improve the determination of phase-shifts at higher energies and impose tight quantitative upper bounds on possible resonant contributions to pp elastic scattering, as they might arise from exotic 6-quark configurations. Recently, with polarized beam and target, the spin-correlation parameters
,
, and
have been determined at 10 energies between 0.8 and 2.5 GeV. The observable
has been measured the first time above 800 MeV and our results are in sharp contrast to phase-shift predictions at higher energies.Received: 30 September 2002, Published online: 22 October 2003PACS:
24.70. + s Polarization phenomena in reactions - 25.40.Cm Elastic proton scattering - 11.80.Et Partial-wave analysis - 13.75.Cs Nucleon-nucleon interactions (including antinucleons, deuterons, etc.) 相似文献
110.
A liquid chromatographic method has been described for the determination of total vitamin C, ascorbic acid (AA) and dehydroascorbic acid (DHAA) in fruits and vegetables. The complete separation of AA and DHAA could be achieved on a C18 column using 0.2 M KH2PO4 (pH adjusted to 2.4 with H3PO4) as the mobile phase at a flow-rate of 0.5 ml/min. Since the detection sensitivity was poor for DHAA even at 210 nm, it was estimated as the difference between the total AA after DHAA reduction and AA content of the original sample, using dithiothreitol (DTT) as the precolumn reductant. The reaction times for the complete conversion of DHAA to AA at room temperatures were 150, 120, 90 and 75 min for 1, 2, 4 and 8 mmol DTT per mmol of DHAA, respectively. The percentage recovery ranged from 81.7 to 105.9. AA contents of some selected fruits and vegetables were analyzed comparatively by liquid chromatography and enzymatic assay to validate the method. 相似文献