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  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 16 (1987), S. 225-235 
    ISSN: 1572-8927
    Keywords: Conductivities ; 1:1 electrolytes ; methyl formate ; ion pairs ; triple ions ; ion solvation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The electrolytic conductivities of LiClO4, LiAlCl4, LiAsF6, NaClO4, NaBPh4, and Bu4NClO4 have been measured in methyl formate at 25°C. Evidence is presented for strong association between the perchlorate ion and the formyl proton of the solvent. Ion association and triple ion formation constants suggest that LiClO4, LiAlCl4, and NaClO4 form solvent separate ion pairs and triple ions. NaBPh4 forms contact ion pairs and triple ions, and the remaining salts appear to form both types of ion pairs and triple ions.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Journal of solution chemistry 18 (1989), S. 977-991 
    ISSN: 1572-8927
    Keywords: Conductivity ; 1∶1 electrolytes ; methyl acetate ; ion pairs ; triple ions ; ion solvation ; activity coefficients
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The electrolytic conductances of NaClO4, NaB(C6H5)4, (n-C4H9)4NClO4 and (n-C4H9)4NPF6 have been measured in methyl acetate at 25°C. A dominating feature of these electrolyte solutions is, as expected, strong ion pairing. In addition it is found that the formation of triple ions makes an important contribution to the overall molar conductivities. The data suggest that there are strong ion-solvent interactions leading to structure-enhanced (after Diamond) ion association and triple ion formation which has an exact analogy in the phenomena of salting-in. The effects of increasing solution permittivity and viscosity are discussed, particularly in regard to comparing two models of treating conductivity data. The first model includes ion pairs and triple ions, and the second model ignores triple ion formation ascribing the anomalous increase in molar conductivities to a decrease in the ion association equilibrium constant caused by increasing solution permittivity.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Medical & biological engineering & computing 38 (2000), S. 653-658 
    ISSN: 1741-0444
    Keywords: Electrogastrography ; Short-bowel syndrome ; Topographic EGG maps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Methods for making topographic or isopower electrogastrographic (EGG) maps and for obtaining maximum power foci (MPFs) by means of 27-channel EGG recordings are briefly described. The methods are applied to short-bowel syndrome (SBS). The gastro-intestinal tract is traced by videofluorograms after X-ray-opaque barium has been ingested. The MPFs are generally located on the trace of the gastrointestinal tract. The gastric area is occupied by 3 cycles min−1 (up to 28% of total MPFs) and 6 cycles min−1 MPFs (26%). The trace of the small intestine is occupied mainly by 8 cycles min−1 (39%) and 10 cycles min−1 (43%) MPFs. The trace of the colon is occupied almost evenly by all five spectral frequency groups, that is, by 1 (58%), 3 (53%), 6 (48%), 8 (57%) and 10 cycles min−1 (42%). Most interestingly, the numbers of 8–10 cycles min−1 power foci found on EGG maps (including MPFs and relatively higher power foci) are proportional to the remaining length at operation and to the length of the remaining small intestine in the long-term, over 6 years post-operatively. It is therefore possible to follow approximately the trace of the gasterointestinal tract.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric surgery international 12 (1997), S. 340-343 
    ISSN: 1437-9813
    Keywords: Esophageal atresia ; Electrogastrography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Esophageal atresia (EA) is a life-threatening disorder associated with operative complications. Post-operative gastric electrical control activity detected by a non-invasive electrogastrography (EGG) technique was investigated in 13 children aged 1–17 years to clarify whether gastric motility disorders were present. EGG abnormalities were present in 5 patients; persistent dysrhythmias were found in 3. Roentgenographic examinations showed mild gastroesophageal reflux in 3 (60%) of the dysrhythmic patients; 2 others had postprandial dysrhythmias. The mean spectral frequency (MSF) of EA cases with dysrhythmia was significantly higher than that of patients without dysrhythmia in both fasting and postprandial states (P 〈 0.05). The variability of the peak spectral frequencies (PSFV) in patients with dysrhythmia was significantly higher than in those without dysrhythmia in both fasting and postprandial states (P 〈 0.05). There were no significant differences in MSF and PSFV between EA patients without dysrhythmia and controls. These results suggest that gastric motor activity may be disordered in patients following operative repair of EA, although they remain asymptomatic. EGG may be a useful screening examination for postoperative gastric functional disorders.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Pediatric surgery international 12 (1997), S. 340-343 
    ISSN: 1437-9813
    Keywords: Key words Esophageal atresia ; Electrogastrography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Esophageal atresia (EA) is a life-threatening disorder associated with operative complications. Postoperative gastric electrical control activity detected by a non-invasive electrogastrography (EGG) technique was investigated in 13 children aged 1–17 years to clarify whether gastric motility disorders were present. EGG abnormalities were present in 5 patients; persistent dysrhythmias were found in 3. Roentgenographic examinations showed mild gastroesophageal reflux in 3 (60%) of the dysrhythmic patients; 2 others had postprandial dysrhythmias. The mean spectral frequency (MSF) of EA cases with dysrhythmia was significantly higher than that of patients without dysrhythmia in both fasting and postprandial states (P 〈 0.05). The variability of the peak spectral frequencies (PSFV) in patients with dysrhythmia was significantly higher than in those without dysrhythmia in both fasting and postprandial states (P 〈 0.05). There were no significant differences in MSF and PSFV between EA patients without dysrhythmia and controls. These results suggest that gastric motor activity may be disordered in patients following operative repair of EA, although they remain asymptomatic. EGG may be a useful screening examination for postoperative gastric functional disorders.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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