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Spin Resonance Technique (spin + resonance_technique)

Distribution by Scientific Domains
Life Sciences75%

Kinds of Spin Resonance Technique

  • electron spin resonance technique
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    Selected Abstracts

    Clinical significance of a highly sensitive enzyme immunoassay of hepatitis B surface antigen using a novel electron spin resonance technique

    JOURNAL OF MEDICAL VIROLOGY, Issue 2 2002
    Masanori Aoki
    Abstract We developed a highly sensitive enzyme immunoassay (EIA), the p-AP/HHTIO method, that detects serum hepatitis B surface antigen (HBsAg) by measuring stabilized nitroxide radicals using a novel electron spin resonance technique [Matsuo et al. (1998) Free Radic Biol Med 25:929,935]. To demonstrate the clinical significance of this method and to reveal occult hepatitis B virus (HBV) infection in patients, we used the method to analyze serum samples of 30 patients with acute or fulminant hepatitis who were negative for HBsAg by standard EIA, and those of seven chronic HBV carriers who became negative for HBsAg during a follow-up period by standard EIA. We also examined serum HBV DNA by amplification of the HBV S gene, using the polymerase chain reaction (PCR) technique. The p-AP/HHTIO method showed that 9 of 20 (45%) patients with acute hepatitis and 2 of 10 (20%) with fulminant hepatitis were positive for HBsAg; PCR detected HBV DNA in these HBsAg-positive patients. Antibody against hepatitis B core antigen was detected in one patient with fulminant hepatitis. The p-AP/HHTIO method demonstrated prolonged seropositivity of HBsAg even after standard EIA showed a loss of HBsAg in all seven HBV carriers. Our p-AP/HHTIO method is useful for screening and diagnosing HBV infection in patients with liver diseases who are negative for conventional HBV-related serological markers. J. Med. Virol. 66:166,170, 2002. © 2002 Wiley-Liss, Inc. [source]

    Photosensitization of Hypomycin B,A Novel Perylenequinonoid Pigment with Only One Intramolecular Hydrogen Bond,

    PHOTOCHEMISTRY & PHOTOBIOLOGY, Issue 2 2001
    Hong-Yu Zhang
    ABSTRACT Electron spin resonance technique and spin-trapping methods were used to determine the photoproduction of 1O2 and O2·, by hypomycin B (HMB), a novel perylenequinonoid pigment (PQP) possessing only one hydroxyl group. It was found that the yields of 1O2 and O2·, for HMB were comparable to those for hypocrellin A, a typical natural PQP with good photosensitivity. In addition, the absorption and fluorescence spectra for HMB were investigated. The pKa values in the ground and excited states of HMB were determined to be 8.94 and 5.54, respectively. Thus, the photodynamic mechanisms of HMB may involve not only the photogeneration of 1O2 and O2·, but also the light-induced acidification. Consequently, HMB is proposed to be a good photodynamic therapeutic agent. [source]

    Electron spin resonance characterization of phosphorus-doped CVD diamond films

    PHYSICA STATUS SOLIDI (A) APPLICATIONS AND MATERIALS SCIENCE, Issue 11 2004
    M. Katagiri
    Abstract Electron spin resonance technique has been applied to characterize defects and to determine local structure of phosphorus in phosphorus-doped (111)-homoepitaxially grown CVD diamond films. Dominant defects have g -value similar to that of the H1 center in polycrystalline CVD diamond, however, are not accompanied with a unique nearby hydrogen atom. These defects are likely to be located near substrate/ epilayer interface. New phosphorus related center with a tetragonal symmetry has been found. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]