381 research outputs found

    ChEBI: a database and ontology for chemical entities of biological interest

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    Chemical Entities of Biological Interest (ChEBI) is a freely available dictionary of molecular entities focused on ‘small’ chemical compounds. The molecular entities in question are either natural products or synthetic products used to intervene in the processes of living organisms. Genome-encoded macromolecules (nucleic acids, proteins and peptides derived from proteins by cleavage) are not as a rule included in ChEBI. In addition to molecular entities, ChEBI contains groups (parts of molecular entities) and classes of entities. ChEBI includes an ontological classification, whereby the relationships between molecular entities or classes of entities and their parents and/or children are specified. ChEBI is available online at http://www.ebi.ac.uk/chebi

    The blue vibronically resolved electroluminescence of azatrioxa[8]circulene

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    Organic Light Emitting Dioides (OLED)devices were fabricated with blue emission based on azatrioxa[8]circulene and 4,4-N,N'-Dicarbazolyl-1,1'-biphenyl (CBP) with maximum brightness of 840 kd/m(2) at 12 V and the starting voltage of 3.5 V. The vibronic emission spectrum was analyzed by the promotive modes calculation method. The electroluminescence of fabricated OLED device is caused by the 0-0 electronic transition and single excitations of 1473 cm(-1) and 1673 cm(-1) modes and combinations thereof.Peer reviewe

    Bioinformatics advances in saliva diagnostics

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    There is a need recognized by the National Institute of Dental & Craniofacial Research and the National Cancer Institute to advance basic, translational and clinical saliva research. The goal of the Salivaomics Knowledge Base (SKB) is to create a data management system and web resource constructed to support human salivaomics research. To maximize the utility of the SKB for retrieval, integration and analysis of data, we have developed the Saliva Ontology and SDxMart. This article reviews the informatics advances in saliva diagnostics made possible by the Saliva Ontology and SDxMart

    Photo- and electroluminescence of new organic semiconductors

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    The results of investigation of the luminescence under photo- and electroexcitation for four new compounds are presented. The spectral properties and photoluminescence are studied in ethanol, chloroform solutions and in films formed by thermovacuum deposition (TVD). The phosphorescence of compounds is investigated in ethanol at 77K temperature. The phosphorescence times of molecules are given. The electroluminescence is obtained in multilayered structure ITO/PEDOT/NPD/L /Ca/Al. It is shown, that spectral region of the photoluminescence of TVD films and electroluminescence coincide. Relations of electroluminescence efficiency with molecule structure, photoluminescence quantum yield and possibility of thermally activated delayed fluorescence are discussed

    Annotations for Rule-Based Models

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    The chapter reviews the syntax to store machine-readable annotations and describes the mapping between rule-based modelling entities (e.g., agents and rules) and these annotations. In particular, we review an annotation framework and the associated guidelines for annotating rule-based models of molecular interactions, encoded in the commonly used Kappa and BioNetGen languages, and present prototypes that can be used to extract and query the annotations. An ontology is used to annotate models and facilitate their description

    Compton Scattering Cross Section on the Proton at High Momentum Transfer

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    Cross-section values for Compton scattering on the proton were measured at 25 kinematic settings over the range s = 5-11 and -t = 2-7 GeV2 with statistical accuracy of a few percent. The scaling power for the s-dependence of the cross section at fixed center of mass angle was found to be 8.0 +/ 0.2, strongly inconsistent with the prediction of perturbative QCD. The observed cross-section values are in fair agreement with the calculations using the handbag mechanism, in which the external photons couple to a single quark.Comment: 5 pages, 5 figure

    Measurement of Inclusive Spin Structure Functions of the Deuteron

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    We report the results of a new measurement of spin structure functions of the deuteron in the region of moderate momentum transfer (Q2Q^2 = 0.27 -- 1.3 (GeV/c)2^2) and final hadronic state mass in the nucleon resonance region (WW = 1.08 -- 2.0 GeV). We scattered a 2.5 GeV polarized continuous electron beam at Jefferson Lab off a dynamically polarized cryogenic solid state target (15^{15}ND3_3) and detected the scattered electrons with the CEBAF Large Acceptance Spectrometer (CLAS). From our data, we extract the longitudinal double spin asymmetry AA_{||} and the spin structure function g1dg_1^d. Our data are generally in reasonable agreement with existing data from SLAC where they overlap, and they represent a substantial improvement in statistical precision. We compare our results with expectations for resonance asymmetries and extrapolated deep inelastic scaling results. Finally, we evaluate the first moment of the structure function g1dg_1^d and study its approach to both the deep inelastic limit at large Q2Q^2 and to the Gerasimov-Drell-Hearn sum rule at the real photon limit (Q20Q^2 \to 0). We find that the first moment varies rapidly in the Q2Q^2 range of our experiment and crosses zero at Q2Q^2 between 0.5 and 0.8 (GeV/c)2^2, indicating the importance of the Δ\Delta resonance at these momentum transfers.Comment: 13 pages, 8 figures, ReVTeX 4, final version as accepted by Phys. Rev.

    Q2Q^2 Dependence of Quadrupole Strength in the γpΔ+(1232)pπ0\gamma^*p\to\Delta^+(1232)\to p \pi^0 Transition

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    Models of baryon structure predict a small quadrupole deformation of the nucleon due to residual tensor forces between quarks or distortions from the pion cloud. Sensitivity to quark versus pion degrees of freedom occurs through the Q2Q^2 dependence of the magnetic (M1+M_{1+}), electric (E1+E_{1+}), and scalar (S1+S_{1+}) multipoles in the γpΔ+pπ0\gamma^* p \to \Delta^+ \to p \pi^0 transition. We report new experimental values for the ratios E1+/M1+E_{1+}/M_{1+} and S1+/M1+S_{1+}/M_{1+} over the range Q2Q^2= 0.4-1.8 GeV2^2, extracted from precision p(e,ep)πp(e,e 'p)\pi^{\circ} data using a truncated multipole expansion. Results are best described by recent unitary models in which the pion cloud plays a dominant role.Comment: 5 pages, 5 figures, 1 table. To be published in Phys. Rev. Lett. (References, figures and table updated, minor changes.
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