Note: Cold spectra of the electronic transition A(2)Σ(+)-X(2)Π of N2O(+) radical: High resolution analysis of the bands 000-100, 100-100, and 001-101.

In this note, three vibrational bands of the electronic transition A(2)Σ(+)-X(2)Π of the N2O(+) radical (000-100, 100-100, and 001-101) were theoretically analysed. Starting from Hamiltonian models proposed for this kind of molecule, their parameters were calculated using a Levenberg-Marquardt fit procedure in order to reduce the root mean square deviation from the experimental transitions below to 0.01 cm(-1). The main objective of this work is to obtain new and reliable values for rotational constant B″ and the spin-orbit interaction parameter A of the analysed vibrational levels of the X(2)Π electronic state of this molecule.

High resolution analysis of three bands of the electronic transition A²Σ⁺-X²Π of N2O⁺ radical: 100-000, 000-001, and 001-001.

In this article three vibrational bands of the electronic transition A(2)Σ(+)-X(2)Π of the N2O(+) radical (100-000, 000-001, and 001-001) are analysed through high resolution Fourier transform spectroscopy. The N2O(+) radical was produced by Penning ionization of N2O by colliding with metastable atoms of He(2(3)S) in a reaction chamber. The spectra was recorded in a spectral range of 24,500-30,000 cm(-1) and obtained from 200 coadded interferograms recorded at an apodized resolution of 0.08 cm(-1). Through a recursive way, the wavenumbers of the correspondent rotational transitions were reduced into molecular constants, improving the values previously reported. New values for the first vibrational energies ν1', ν3", and ν3' are also obtained and compared with previous values reported in the literature.

Improved molecular constants of the 000-000 band of the electronic transition A2Σ+-X2Π of N2O+ radical.

In this paper the 000-000 vibrational band of the electronic transition A(2)Σ(+)-X(2)Π of the N2O(+) radical is analyzed, through high resolution Fourier Transform spectroscopy. The N2O(+) radical was produced by Penning ionization of N2O by colliding with metastable atoms of He(2(3)S) in a vacuum chamber. The spectrum was recorded in a spectral range of 24,500-30,000 cm(-1) and obtained from 200 coadded interferograms recorded at an apodized resolution of 0.08 cm(-1). Through a recursive way, the wavenumbers of the correspondent rotational transitions were reduced into molecular constants. A total of 280 lines were adjusted to the model with a standard deviation of 0.006 cm(-1).

Light transmission on dental resin composites.

OBJECTIVES: The purposes of this study was: (1) to examine the light transmittance characteristics of two light-cured resin composites, for different thickness, (2) to correlate the light transmittance through the resin composites and the filler contents, and (3) to determine the penetration depth of the light as a function of the wavelength. METHODS: Two resin composites (Filtek Z250, shade A2 and Filtek Supreme XT, shade A2E) were used. Specimens of six different thicknesses (0.15, 0.25, 0.30, 0.36, 0.47 and 0.75 mm) were prepared (n=3). The transmittance at wavelengths from 400 to 800 nm was measured using a UV-visible spectrophotometer, before and after light polymerization. RESULTS AND SIGNIFICANCE: Significant differences were found in the wavelength dependence of transmittance between the two materials, and between the unpolymerized and polymerized stages of each resin composite. At lower wavelengths, the light transmittance of the Filtek Supreme XT resin composite was lower than the Filtek Z250. At the higher wavelengths, however, Filtek Supreme XT presented higher light transmittance. For both resin composites, the penetration depth was higher after polymerization. However, Filtek Supreme XT showed a higher gain in transmittance at the 0.15 mm thickness. The difference in light transmittance characteristics of the resin composites may affect their depth of polymerization.

Further characterization of endopeptidase H2 a serine proteinase from human urine.

A human urine serine proteinase chymotrypsin like hydrolyzes the peptide bonds: Phe-Ser (kinin); Gly-Gly, Leu-Arg, Phe-Lys (neuropeptides) and Gln-Gln (substance P). Endopeptidase H2 hydrolyzes better oligopeptides with 4 to 18 aminoacid residues than larger peptides, it does not hydrolyzes kininogen or proenkephalin. The enzyme behaves as an oligoendopeptidase.