Aromaticity and tautomerism—VII: Empirical resonance energy and conjugation energy of pyrazole and isoxazole from heats of dehydration data

The dehydration of various 4,5-dihydro-4- and -5-hydroxy derivatives of pyrazole and isoxazole has been investigated. Heats of dehydration of 4,5-duiydro-4-hydroxy-1,3,5-tripbenylpyrazole and 4,5-dihydro-5-hydroxy-isoxazole are evaluated and used to assess the empirical resonance energy and conjugation energy of pyrazole and isoxazole. The former possesses resonance stabilisation comparable to pyrrole but that of the latter is low.     

Rapid identification of environmental bacterial strains by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

In recent years, various mass spectrometry procedures have been developed for bacterial identification. The accuracy and speed with which data can be obtained by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS) could make this a powerful tool for environmental monitoring. However, minor variations in the sample preparation can influence the mass spectra significantly. Therefore, the first objectives of this study were the adjustment and the optimization of experimental parameters allowing a rapid identification of whole bacterial cells without laborious sample preparation. The tested experimental parameters were matrix, extraction solvent, salt content, deposition method, culture medium and incubation time. This standardized protocol was applied to identify reference and environmental bacterial strains of Escherichia coli, Salmonella and Acinetobacter. The environmental bacterial strains were isolated from sewage sludge using an original microextraction procedure based on repeated sonications and enzymatic treatments. The bacterial identification was realized by the observation of the respective genus-, species- and strain-specific biomarkers. This bacterial taxonomy could be completed within one hour, with minimal sample preparation, provided that sufficient bacteria had been collected prior to MALDI-TOF analysis.     

Growth of vertical and defect free InP nanowires on SrTiO3(001) substrate and comparison with growth on silicon

We present a study of the molecular beam epitaxy of InP nanowires (NWs) on (001) oriented SrTiO₃ (STO) substrates using vapor liquid solid mechanism and gold–indium as metal catalyst. The growth direction of InP NWs grown on STO(001) is compared with NWs grown on (001) and (111) oriented silicon substrates. Gold–indium dewetting under a flux of indium results in the majority of InP NWs growing vertically from the surface of STO(001). With the growth parameters we have used the NWs have a pure wurtzite structure and are free of stacking faults and cubic segments. The structural quality of the NWs is confirmed by micro-photoluminescence measurements showing a narrow peak linewidth of 6.5 meV.     

Zur Theorie der Kaltvulkanisation des Kautschuks

Ohne Zusammenfassung(Vorläufige Mitteilung aus dem Kgl. Materialprüfungsamte zu Groß-Lichterfelde-West.)     

Über die Lösungen der linearen partiellen Differentialgleichungen zweiter Ordnung vom elliptischen Typus

Ohne Zusammenfassung