Acoustic Analyses of Developmental Changes and Emotional Expression in the Preverbal Vocalizations of Infants

The nonverbal vocal utterances of seven normally hearing infants were studied within their first year of life with respect to age- and emotion-related changes. Supported by a multiparametric acoustic analysis it was possible to distinguish one inspiratory and eleven expiratory call types. Most of the call types appeared within the first two months; some emerged in the majority of infants not until the 5th (“laugh”) or 7th month (“babble”). Age-related changes in acoustic structure were found in only 4 call types (“discomfort cry,” “short discomfort cry,” “wail,” “moan”). The acoustic changes were characterized mainly by an increase in harmonic-to-noise ratio and homogeneity of the call, a decrease in frequency range and a downward shift of acoustic energy from higher to lower frequencies. Emotion-related differences were found in the acoustic structure of single call types as well as in the frequency of occurrence of different call types. A change from positive to negative emotional state was accompanied by an increase in call duration, frequency range, and peak frequency (frequency with the highest amplitude within the power spectrum). Negative emotions, in addition, were characterized by a significantly higher rate of “crying,” “hic” and “ingressive vocalizations” than positive emotions, while positive emotions showed a significantly higher rate of “babble,” “laugh,” and “raspberry.”     

Synthesis and rapid enantiomeric separation of the chiral mixed ligand [5-(4-hydroxybutyl)-5′-methyl-2,2′-bipyridine]-bis(1,10-phenanthroline)-ruthenium(II) complex by electrokinetic chromatography

The chiral complex [5-(4-hydroxybutyl)-5′-methyl-2,2′-bipyridine]-bis(1,10-phenanthroline)ruthenium(II)-bis(hexafluoroantimonate) was successfully synthesized and fully characterized by two-dimensional ¹H and ¹³C{¹H} NMR techniques (COSY and HMQC) as well as EA- and FAB-MS. A very fast separation of the Δ and Λ enantiomers with excellent efficiency and resolution was achieved by electrokinetic chromatography using anionic carboxymethyl-β-cyclodextrin as a chiral mobile phase additive. The optimum separation conditions were obtained with 50 mM borate buffer at pH 9 and 10 mg/ml of the chiral selector at 20°C. Attempts to separate the well known unmodified tris(2,2′-bipyridine)ruthenium(II) [Ru(bpy)₃] complex into its enantiomers under the same conditions were unsuccessful.     

Ultramicrobiosensor for the Selective Detection of Glutamate

Carbon fiber microelectrodes, able to detect catecholamine release from single cells, have significantly contributed to our present understanding of the mechanism of secretory neurotransmission. In spite of their obvious advantages, there are only a few amperometric sensors (characterized by appropriate size, sensitivity, and selectivity) able to measure the release of other (not easily oxidizable) neurotransmitters at cellular level. The present work describes the fabrication and characterization of an ultramicrobiosensor for the selective detection of glutamate. The developed sensor has a size of 2.5–15 μm in diameter, a sensitivity of 0.62 mA mM^?1 cm^?2, and a detection limit of 5 μM. The excellent selectivity of the sensor (achieved using electrodeposition of Ru, Rh, and poly(m‐phenylenediamine)) makes it a promising candidate for monitoring glutamate release at single cell level.     

Synthesis,Crystal Structure Determination from X‐Ray Powder Diffractometry and Vibrational Spectroscopic Properties of Mg[N(CN)2]2 · 4 H2O

Magnesium dicyanamide tetrahydrate Mg[N(CN)₂]₂ · 4 H₂O was synthesized by aqueous ion exchange starting from Na[N(CN)₂] and Mg(NO₃)₂ · 6 H₂O. The crystal structure was solved and refined on the basis of powder X‐ray diffraction data (P2₁/c, Z = 2, a = 737.50(2), b = 732.17(1), c = 971.67(2) pm, β = 98.074(1)°, wR_p = 0.059, R_p = 0.046, R_F = 0.075). In the crystal there are neutral complexes [Mg[N(CN)₂]₂(H₂O)₄] which are only connected via hydrogen bonds. Above 40 °C the tetrahydrate decomposes into anhydrous Mg[N(CN)₂]₂.     

Alkylation des β-énaminoesters cycliques: Relation entre la taille et la réactivité

Cyclic β-enaminoesters are C-alkylated. Experimental conditions are different according to the ring size, mild with large rings and drastic with small rings where the conjugation is more important. Physical data allow an explanation between the ring size of β-enaminoesters and their reactivity.     

Anwendung derR-Wert-Methode auf isokonformere Cyclohexane: Kernsubstituierte [2.2]Metacyclophane

The applicability of theLambert-Buys-Criterion (R-Value-Method) is tested for the ten-membered ring of [2.2]metacyclophane. The torsional angles thus obtained from the vicinal proton spin coupling constants are in accordance with X-ray data and recent force field calculations. Consequently, further investigations could be performed regarding the changes of the basic geometry in substituted [2.2]metacyclophanes. Fourteen derivatives with different substituents and substitution patterns were studied and their conformational changes are discussed.

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VonH. Lehner auszugsweise vorgetragen am Organisch-Chemischen Institut der Reichsuniversität Gent, Belgien, am 27. Mai 1975.     

Polychloroformiate de vinyle: Support inerte de principes actifs,fixation et hydrolyse in vitro de sympathomimétiques

The chemical modification of poly(vinyl chloroformate) with sympathomimetics (phenyl ethylamine, ephedrine, p-hydroxyephedrine and p-hydroxymorephedrine) has been investigated. We have found convenient conditions to obtain soluble modified polymers with nearly quantitative substitution. The use of labelled compounds has shown that the rate and the yield of fixation on the polymer are independent of the nature of the amine. Kinetics in vitro of cleavage has shown that the rates of hydrolysis in stomacal, intestinal and enzymatic media are very low and similar; the observed variations seem to result from differences in solubility of the various modified polymers.