Chemiluminescence levels

Hypolipemic activity. Fiber, administered orally to nine adults with ileostomies at a dose of 13 g/day, increased the excretion of cholesterol " Petroleum ether extract of the fresh fruit, administered to pigs at a concentration of 3.5 g/kg of diet, was inactive "" . Purified green barley extract, in human mononuclear culture of cells isolated from perithelial blood and synovial fluid of patients with rheumatoid arthritis, was active . Leaf essence, administered to atherosclerotic New Zealand White male rabbits at a dose of 1% of diet, produced a decrease of plasma total cholesterol, triacylglycerol, lucigenin-chemilumines-cence, and luminal-chemiluminescence levels. The value of Tj of red blood cell hemolysis and the lag phase of LDL oxidation increased in barley-treated group compared with the control. Ninety percent of the intimal surface of the thoracic aorta was covered with atherosclerotic lesions in the... 

Phagocytosis of opsonized zymosan particles produced chemiluminescence in PMNs, which was reduced by shear stress exposures of 100 and 300 dyn/cm2 (Figure 3). Peak chemiluminescence levels were reduced to 74.4 10% of unsheared control values by exposure to 100 dyn/cm2, and to 67 5% of control values after exposure to 300 dyn/cm2. Following preincubation with PGE and RA-233, similar decreases in chemiluminescence with shear exposure occurred. However, although not shown in the graph, the cell suspensions receiving shear stress tended to achieve peak values of chemiluminescence somewhat more slowly than the unsheared sample. 

The first mfonnation on the HE vibrational distribution was obtained in two landmark studies by Pimentel [39] and Polanyi [24] in 1969 both studies showed extensive vibrational excitation of the HE product. Pimental found that tire F + H2 reaction could pump an infrared chemical laser, i.e. the vibrational distribution was inverted, with the HF(u = 2) population higher than that for the HF(u = 1) level. A more complete picture was obtained by Polanyi by measuring and spectrally analysing tlie spontaneous emission from vibrationally excited HE produced by the reaction. This infrared chemiluminescence experiment yielded relative populations of 0.29, 1 and 0.47 for the HF(u =1,2 and 3)... 

High quantum yields are uncommon and, moreover, the quantum yield almost always decreases as the concentration of chemiluminescent reactant approaches practical levels. Thus even reactions with high inherent quantum yields at low concentrations, such as the firefly reaction, do not necessarily provide high light capacities (237). 

O ne. Air pollution (qv) levels are commonly estimated by determining ozone through its chemiluminescent reaction with ethylene. A relatively simple photoelectric device is used for rapid routine measurements. The device is caHbrated with ozone from an ozone generator, which in turn is caHbrated by the reaction of ozone with potassium iodide (308). Detection limits are 6—9 ppb with commercially available instmmentation (309). 

Concerns over safe handling of radioactive materials and issues around the cost and disposal of low level radioactive waste has stimulated the development of nonradiometric products and technologies with the aim of replacing radioactive tracers in research and medical diagnosis (25). However, for many of the appHcations described, radioactive tracer technology is expected to continue to be widely used because of its sensitivity and specificity when compared with colorimetric, fluorescent, or chemiluminescent detection methods. 

The efficient recovery of volatile nitrosamines from frankfurters, followed by gc with chemiluminescence detection, has been described (133). Recoveries ranged from 84.3 to 104.8% for samples spiked at the 20 ppb level. Methods for herbicide residues and other contaminants that may also relate to food have been discussed. Inorganic elements in food can be deterrnined by atomic absorption (AA) methods. These methods have been extensively reviewed. Table 8 Hsts methods for the analysis of elements in foods (134). 

The flame-photometric detector (FPD) is selective for organic compounds containing phosphoms and sulfur, detecting chemiluminescent species formed ia a flame from these materials. The chemiluminescence is detected through a filter by a photomultipher. The photometric response is linear ia concentration for phosphoms, but it is second order ia concentration for sulfur. The minimum detectable level for phosphoms is about 10 g/s for sulfur it is about 5 x 10 g/s. 

Anions of another group were derivatized with formation of gaseous chemiluminescing species. Chemical reaction - gas extraction has been used with chemiluminescence detection in the stream of canier gas in on-line mode. Rate of a number of reactions has been studied as well as kinetic curves of extraction of gaseous products. Highly sensitive and rapid hybrid procedures have been developed for the determination of lO, BrO, CIO, CIO, NO,, N03, CrO, CIO, Br, T, S, 803 with detection limits at the level of pg/L, duration of analysis 3 min. 

A note on the assays of coelenterazine and luciferase activity. The methods for measuring coelenterazine and the corresponding luciferases are given in Appendix C5. Special attention must be paid to the fact that coelenterazine in aqueous buffer solutions spontaneously emits a low level of chemiluminescence in the absence of any luciferase, which is greatly enhanced by the presence of various substances, including egg yolk, BSA and various surfactants (especially, hexadecyltrimethylammonium bromide). Therefore, the utmost care must be taken in the detection and measurement of a low level of... 

Treatment of the precursors with decylamine resulted in a high level of chemiluminescence activity. Taking the activity obtained with decylamine as 100%, the activities obtained with other amines were methylamine, 5% hexylamine, 23% octylamine, 39% and dode-cylamine, 55%. For comparison, the Panellus precursors, PS-A and PS-B, are best activated with methylamine, and a synthetic model compound, K-l, is best activated with hexylamine. 

In bioluminescence and chemiluminescence reactions, light is emitted when the energy level of light emitter molecules falls from the excited state to the ground state. The quantum yield Q of the substance A is given by ... 

Stanley, P. E. (1997). Commercially available luminometers and imaging devices for low-light level measurements and kits and reagents utilizing bioluminescence or chemiluminescence survey update 5. /. Biolumin. Chemilumin. 12 61-78. 

NAKAGAWA K and MIYAZAWA T (1997) Chemiluminescence-high-performance liquid chromatographic determination of tea catechin, (-)-epigallocatechm 3-gallate, at picomole levels in rat and human plasma , Anal Biochem, 248, 41-9. 

Chemiluminescence has been used to demonstrate increased free-radical activity after induction of caerulein pancreatitis, with levels peaking at about 20 min and decreasing rapidly to control values thereafter (Gough et al., 1990). Electron spin resonance has been used to demonstrate increased hydroxyl radical activity in choline-deficient diet pancreatitis in the mouse (Nonaka etal., 1989a). 

Keshavarzian, A., Zapeda, D., List, T. and Mobarhan, S. (1992d). High levels of reactive oxygen metabolites in colon cancer tissues analysis by chemiluminescence probe. Nutr. Cancer 17, 243-249. 

Carbon impregnated with potassium iodide was used as an ozone-scrubbing filter in a chemiluminescence NO analyser. When the level of iodide was inadvertently increased to the high level of 40%, the filter exploded violently dining replacement after use. This was attributed to oxidation of iodide to iodate by ozone, and frictional initiation of the iodate-carbon mixture when the filter was dismantled. 

Provided that chemiluminescence intensity Iql is proportional to the rate of peroxyl radicals termination, that is Icl [PO ]2, which is often assumed in the literature, chemiluminescence intensity should achieve some quasi-stationary level when hydroperoxide concentration becomes stationary and its decay should correspond to consumption of oxidizable groups, PH, in a polymer. At the same time, the chemiluminometric curves of type (a), which are typical with an autoaccelerating increase of the light emission (Figure 4) are relevant for... 

Observations Table 2 shows the levels of free radicals determined by luminol chemiluminescence, H202 levels, and membrane lipid peroxidation determined by conjugated dienes. Total free radicals significantly increased by 1.4 fold, hydrogen peroxide significantly decreased 1.3 fold, and lipid peroxidation increased significantly 1.5 fold. 

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