Rapid micro combustion methods for the determination of elements in organic compounds

Summary Advantages of the rapid combustion process for the micro determination of carbon and hydrogen, sulphur, and halogen are discussed, and methods for their estimation are described which have been adopted for routine analysis.

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Zusammenfassung Die Vorteile eines raschen Verbrennungsvorganges für die Mikrobestimmung von Kohlenstoff, Wasserstoff, Schwefel und Halogen werden beschrieben. Methoden für deren quantitative Bestimmung, die sich besonders für Serienanalysen bewährt haben, werden mitgeteilt.

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Résumé On discute les avantages du procédé rapide de combustion pour le microdosage du carbone, de l'hydrogène, du soufre et des halogènes et l'on décrit les méthodes pour leur dosage qui ont été adaptées dans les analyses en série.

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With 5 Figures.     

Copper(II) complexes of 2-formyl-, 2-acetyl- and 2-benzoyl-pyridine N(4)-phenyl-, N(4)-o-methoxyphenyl-, N(4)-p-methoxy-phenyl- and N(4)-p-nitrophenylthiosemicarbazones

Summary Cu^II complexes of 2-formyl-, 2-acetyl- and 2-benzoylpyridine N(4)-phenyl-, N(4)-o-methoxyphenyl-, N(4)-p-methoxyphenyl- and N(4)-p-nitrophenyltniosemicarbazones, coordinated either as neutral or monoanionic ligands, have been prepared and characterized. I.r., electronic and e.p.r. spectra of the complexes, as well as ¹H-and ¹³C-n.m.r. spectra of the thiosemicarbazones, have been obtained. Both the thiosemicarbazones and their complexes show either modest or no growth inhibitory activity against Paecilomyces variotii. However, some of these thiosemicarbazones possess significant activity against a number of tumour cell strains.     

Small angle neutron scattering studies on micellar systems part 2. Mixed systems of ammonium decanoate and ammonium perfluoro-octanoate

Mixtures of ammonium decanoate (AmDec) and ammonium perfluoro-octanoate (APFO), in ammonium chloride: ammonium hydroxide buffer at pH 8.8 and an ionic strength of 0.1, were examined by small angle neutron scattering with varying proportions of the two surface active agents. The results indicated that mixed micelles were formed and it is suggested from analysis of the data that these were cylindrical in shape at APFO: AmDec ratios of 21, 11 and 12. At 21 and 11 the micelles were found to contain more APFO than expected on the basis of ideal mixing of the surface active agents in the micelle. At a ratio of 19 the micelles were found to be spherical but larger than those formed from AmDec alone. A speculative model is proposed for the mixed micelle which still, however, allows for segregation between hydrocarbon and fluorocarbon chains within the micelle.     

Diophantine analysis and torsion on elliptic curves

In a recent paper of Bennett and the author, it was shown thatthe elliptic curve defined by y² = x³ + Ax + B, where A andB are integers, has no rational points of finite order if Ais sufficiently large relative to B (at least if one assumesthe abc Conjecture of Masser and Oesterlé). In the presentarticle we show, perhaps surprisingly, that the rational torsionon the above curve is also quite restricted if B is sufficientlylarge relative to A. In particular, we demonstrate that forany > 0 there is a constant c such that if A and B are integerssatisfying |B| > c |A|⁶⁺, then the elliptic curve definedabove has no rational torsion points, other than a possiblepoint of order 2 (again making use of the abc Conjecture insome cases). We then extend this by proving similar resultsfor elliptic curves admitting non-trivial -isogenies, ellipticcurves written in other forms, and elliptic curves over certainnumber fields. Curiously, the results on isogenies lead to twounexpected irrationality measures for certain algebraic numbers.     

Acoustic and perceptual cues for compound-phrasal contrasts in Vietnamese

This paper reports two series of experiments that examined the phonetic correlates of lexical stress in Vietnamese compounds in comparison to their phrasal constructions. In the first series of experiments, acoustic and perceptual characteristics of Vietnamese compound words and their phrasal counterparts were investigated on five likely acoustic correlates of stress or prominence (f0 range and contour, duration, intensity and spectral slope, vowel reduction), elicited under two distinct speaking conditions: a "normal speaking" condition and a "maximum contrast" condition which encouraged speakers to employ prosodic strategies for disambiguation. The results suggested that Vietnamese lacks phonetic resources for distinguishing compounds from phrases lexically and that native speakers may employ a phrase-level prosodic disambiguation strategy (juncture marking), when required to do so. However, in a second series of experiments, minimal pairs of bisyllabic coordinative compounds with reversible syllable positions were examined for acoustic evidence of asymmetrical prominence relations. Clear evidence of asymmetric prominences in coordinative compounds was found, supporting independent results obtained from an analysis of reduplicative compounds and tone sandhi in Vietnamese [Nguye;n and Ingram, 2006]. A reconciliation of these apparently conflicting findings on word stress in Vietnamese is presented and discussed.     

Aminosalicylic acid conjugates of EDTA as potential anti-inflammatory pro-drugs: synthesis,copper chelation and superoxide dismutase-like activities

Aminosalicylic acids have been used to combat inflammatory bowel diseases (IBDs) for over 60 years. In this report, spectroscopic studies on the Cu(II) complexation behaviour of the newly synthesised chelator ethylenediaminetetraacetic acid bis-(4-aminosalicylic acid methyl ester) (4-EBAME), and the regiostereoisomer ethylenediaminetetraacetic acid bis-(5-aminosalicylic acid methyl ester) (5-EBAME) are presented. Both conjugates bind to Cu(II) in an ideal 1:1 ratio, as shown by Job’s method and spectroscopic titrations. 5-EBAME was screened in the NCI 60 cancer cell-line and showed anti-cancer properties. Neither of the conjugates were degraded by bovine liver protease, although some de-esterification was seen at high pH over a 24-h period. These two conjugates show potential as metal chelating anti-oxidants for use against IBDs.     

Pion absorption reactions on N, Ar and Xe

The absorption of π⁺ on Ar was studied at pion energies of 70, 118, 162, 239 and 330MeV, and on N and Xe at 239MeV. Twenty-six absorption reaction channels with at least two energetic charged particles in the final state have been evaluated. Partial cross-sections have been determined according to the number of protons, neutrons and deuterons in the final state. Received: 16 October 2000 / Accepted: 1 December 2000