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  • 1995-1999  (1)
  • 1985-1989  (2)
  • Baroreflex sensitivity  (1)
  • Extraction-spectrophotometric determination  (1)
  • Fading phenomena  (1)
  • Nuclear Reactions
  • Nuclear reactions
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  • 1995-1999  (1)
  • 1985-1989  (2)
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  • 1
    ISSN: 1435-1536
    Keywords: Fading phenomena ; azo oil dye ; solution properties ; mixed surfactant system ; anionic-nonionic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The effects of alkyl and/or oxyethylene groups in a nonionic surfactant on the fading phenomena of 4-phenylazo-1-naphthol (4-OH), which occur in aqueous solutions of anionic-nonionic surfactant systems, are described; these systems are sodium dodecyl sulfate (SDS) — alkyl poly(oxyethylene) ethers (CmPOEn, m=12,14,16, and 18 at n=20; n=10, 20, 30, and 40 at m=16). The fading phenomenon is observed when 4-OH is added to the anionic-nonionic mixed surfactant solutions at a molar ratio of 1∶1. A singlet oxygen, which is caused by the hydrophilic-hydrophilic interaction between two surfactants, is thought to attack the tautomer of 4-OH. The fading rate of 4-OH accelerates with increasing alkyl chain length or with decreasing oxyethylene chain length in the nonionic surfactant molecule. The effect on the fading behavior of 4-OH would be larger for a system which can easily form a mixed micelle than for a system in which two kinds of micelles coexist.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 1432-1041
    Keywords: Key words Alacepril ; Baroreflex sensitivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Abstract Objective: Patients with heart failure have abnormal neurohormonal regulation during orthostatic stress, and abnormal arterial baroreflex function. This study investigated the effects of alacepril, a new angiotensin-converting enzyme inhibitor with sulfhydryls, on changes in neurohormonal factors during tilt and on the arterial baroreflex control of heart rate. Methods: Plasma concentrations of noradrenaline, adrenaline, renin activity, angiotensin II, and atrial natriuretic peptide were measured at supine rest and after 30° head-up tilt with measurements of central venous pressure and cardiac dimensions in seven patients with congestive heart failure (65 years, ejection fraction = 34%). Arterial baroreflex control of heart rate was assessed by phenylephrine bolus. The arterial baroreflex test was re-examined 3 h after oral alacepril (37.5 mg). The tilt and arterial baroreflex tests were repeated 12 weeks after alacepril treatment (50 mg␣·␣day−1). Results: Heart rate, blood pressure, and neurohormonal factors did not differ before and after chronic alacepril, except for a trend toward an increase in renin activity (2.0 vs 4.9 ng · ml−1· h−1). Head-up tilt decreased central venous pressure (−2.5 mmHg) with a decrease in cardiac dimensions in the pre-alacepril phase. These changes were accompanied by increases in noradrenaline, adrenaline, and angiotensin II and a decrease in atrial natriuretic peptide. After chronic alacepril, the increase in noradrenaline during head-up tilt tended to be smaller (84 vs 30 pg · ml−1), with similar changes in central venous pressure (−3.4 mmHg) and cardiac dimensions. Both acute (3.6 vs 4.8 ms · mmHg−1) and chronic (3.6 vs 6.7 ms · mmHg−1) alacepril treatment was associated with a trend towards an increase in the arterial baroreflex control of heart rate. Conclusion: These results suggest that treatment with alacepril may cause a reduction of sympathetic activation during orthostatic stress and may enhance arterial baroreflex function in patients with mild to moderate heart failure.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 266 (1988), S. 475-478 
    ISSN: 1435-1536
    Keywords: Extraction-spectrophotometric determination ; anionic surfactant ; phase transition ; multiphase microemulsion systems
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The determination of anionic surfactant contents in multiphase microemulsions, based on the extraction-spectrophotometric method, has been carried out. The multiphase microemulsion system we studied is composed of sodium octyl sulfate (SOS), n-hexanol, n-decane, and brine. The system shows Winsor type phase-transitions (Winsor I type ↔ Winsor III type ↔ Winsor II type) with changing salinity. We found that the extraction-spectrophotometric method used here is very useful for the determination of anionic surfactants in any microemulsion phases: the partition ratios of SOS in two different phases change continuously within the salinity region at which the phase transition takes place.
    Type of Medium: Electronic Resource
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