117 research outputs found

    On determination of electronic-vibro-rotational term values of diatomic molecules from measured wavenumbers

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    A method is proposed for determining rovibronic term values of diatomics from experimental data on the wavenumbers of electronic-vibro-rotational spectral lines. In contrast to existing techniques, the new one is based on the Rydberg-Ritz principle only. It is shown that a link between a set of rovibronic term values and a set of wavenumbers of observed rovibronic spectral lines appears when three and more different electronic-vibrational states are pairwise-connected by radiative transitions. The method differs from known techniques in several aspects, namely, it: 1) doesn't need any assumptions concerning an internal structure of a molecule; 2) doesn't involve any intermediate parameters (as molecular constants in traditional techniques); 3) gives an opportunity to use in one-stage optimization procedure all available experimental data obtained for various band systems, by various authors, and in various works; 4) provides in an interactive mode the opportunity to select the experimental values, eliminating rough errors, to revise wrong identifications of spectral lines and to compare various sets of experimental data for mutual consistency; 5) allows to obtain not only an optimal set of rovibronic term values, but also the error bars depending on quantity and quality of existing experimental data. Necessary precondition for use of this method is a preliminary identification of electronic-vibro-rotational lines to certain electronic-vibro-rotational radiative transitions. For this purpose one has to use traditional methods of the analysis of molecular spectra.Comment: 10 pages, 2 figures, in Russia

    The Short Non-Coding Transcriptome of the Protozoan Parasite Trypanosoma cruzi

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    The pathway for RNA interference is widespread in metazoans and participates in numerous cellular tasks, from gene silencing to chromatin remodeling and protection against retrotransposition. The unicellular eukaryote Trypanosoma cruzi is missing the canonical RNAi pathway and is unable to induce RNAi-related processes. To further understand alternative RNA pathways operating in this organism, we have performed deep sequencing and genome-wide analyses of a size-fractioned cDNA library (16–61 nt) from the epimastigote life stage. Deep sequencing generated 582,243 short sequences of which 91% could be aligned with the genome sequence. About 95–98% of the aligned data (depending on the haplotype) corresponded to small RNAs derived from tRNAs, rRNAs, snRNAs and snoRNAs. The largest class consisted of tRNA-derived small RNAs which primarily originated from the 3′ end of tRNAs, followed by small RNAs derived from rRNA. The remaining sequences revealed the presence of 92 novel transcribed loci, of which 79 did not show homology to known RNA classes

    Protein disulphide isomerase-assisted functionalization of proteinaceous substrates

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    Protein disulphide isomerase (PDI) is an enzyme that catalyzes thiol-disulphide exchange reactions among a broad spectrum of substrates, including proteins and low-molecular thiols and disulphides. As the first protein-folding catalyst reported, the study of PDI has mainly involved the correct folding of several cysteine-containing proteins. Its application on the functionalization of protein-based materials has not been extensively reported. Herein, we review the applications of PDI on the modification of proteinaceous substrates and discuss its future potential. The mechanism involved in PDI functionalization of fibrous protein substrates is discussed in detail. These approaches allow innovative applications in textile dyeing and finishing, medical textiles, controlled drug delivery systems and hair or skin care products.We thank to FCT 'Fundacao para a Ciencia e Tecnologia' (scholarship SFRH/BD/38363/2007) for providing Margarida Fernandes the grant for PhD studies

    Russia’s idea of the multipolar world order: origins and main dimensions

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    Contemporary international relations are rife with the ideological struggle over the potential nature of the rapidly changing world order. Two distinct paradigmatic positions have surfaced. One champions economic, cultural, and political globalization conducted under the leadership of the Western world. The other advocates a more particularistic approach that fends for a balance of interests, multiplicity of politico-cultural forms and multiple centers of international influence. The latter doctrine, often referred to as the multipolar world theory, is the subject of this paper. The discussion argues that the idea of a multipolar world order has emerged as Russia’s main ethical and ideological position advanced in the international arena. Its philosophical tenets buttress Russian society intellectually at home, providing the expedients to pursue the country’s foreign policy goals abroad. The paper examines a substantial value package with roots in both Russian and Western philosophy that sustains the multipolar world order theory

    Surfing the spectrum - what is on the horizon?

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    Diagnostic imaging techniques have evolved with technological advancements - but how far? The objective of this article was to explore the electromagnetic spectrum to find imaging techniques which may deliver diagnostic information of equal, or improved, standing to conventional radiographs and to explore any developments within radiography which may yield improved diagnostic data. A comprehensive literature search was performed using Medline, Web of Knowledge, Science Direct and PubMed Databases. Boolean Operators were used and key-terms included (not exclusively): terahertz, X-ray, ultraviolet, visible, infra-red, magnetic resonance, dental, diagnostic, caries and periodontal. Radiographic techniques are primarily used for diagnostic imaging in dentistry, and continued developments in X-ray imaging include: phase contrast, darkfield and spectral imaging. Other modalities have potential application, for example, terahertz, laser doppler and optical techniques, but require further development. In particular, infra-red imaging has regenerated interest with caries detection in vitro, due to improved quality and accessibility of cameras. Non-ionising imaging techniques, for example, infra-red, are becoming more commensurate with traditional radiographic techniques for caries detection. Nevertheless, X-rays continue to be the leading diagnostic image for dentists, with improved diagnostic potential for lower radiation dose becoming a reality
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