Profile structures of ultrathin periodic and nonperiodic multilayer films containing a disubstituted diacetylene by high-resolution x-ray diffraction.
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Journal Article↗
Biomedical subjects
M Filipkowski
Publications and source records attributed to M Filipkowski.
Profile structures of very thin multilayers by x-ray diffraction using direct and refinement methods of analysis.
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Journal Article↗
Organ chemiluminescence: noninvasive assay for oxidative radical reactions.
In situ and perfused rat livers showed a spontaneous chemiluminescence of 7-12 counts/sec . cm2 (corresponding to 7-12 x 10(3) photons/sec . cm2); chemiluminescence was increased up to 30 times by infusion of exogenous hydroperoxides. The chemiluminescence of the perfused liver was oxygen dependent. Ethyl, t-butyl, and cumene hydroperoxides were almost equally effective in inducing light emission in the perfused liver. Glutathione release and chemiluminescence showed a parallel increase upon hydroperoxide supply to the perfused liver. A partial spectral analysis of the chemiluminescence of the perfused liver showed a predominance of red-light-emitting species, presumably arising from the singlet oxygen dimol-emission peaks. Many side reactions derived from the complex free radical sequence of lipid peroxidation could afford the chemistry leading to light emission, which represents only about 10(-14) of the utilization of peroxide.
Animals↗
Chemiluminescence of Acanthamoeba castellanii.
1. Chemiluminescence of Acanthomoeba castellanii in the presence of O2 was of similar intensity in organisms harvested early or late during exponential growth [when cyanide (1 mM) stimulates or inhibits respiration respectively]. 2. Cyanide (up to 1.5 mM) stimulated photoemission in both types of organism by 250--300 photons/s per 10(7) cells above the value observed under aerobic conditions. 3. 'Dibromothymoquinone' (2,5-dibromo-6-isopropyl-3-methyl-p-benzoquinone) (up to 80 microM) further increased chemiluminescence. 4. Similar responses were also demonstrated in whole homogenates and in subcellular fractions; 36% of the chemiluminescence was provided by a fraction sedimenting at 100000g-min, and 20% in that fraction that was non-sedimentable at 200000g-min. 5. Mitochondrial substrates (succinate, 2-oxoglutarate, NADH) in the presence or absence of ADP and Pi or peroxisomal substrates (glycollate, urate or ethanol) gave no increases in light emission by whole homogenates or in any of the fractions. 6. It is suggested that reactions responsible for production of chemiluminescence are those primarily producing superoxide anions and leading to lipid peroxidation and singlet-oxygen formation. Photoemission enhancement and superoxide dismutase inhibition showed similar cyanide concentration-dependencies.
Amoeba↗