756 research outputs found

    a fascinating and neglected pathogen

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    Hepatitis delta virus (HDV) is the etiologic agent of the most severe form of virus hepatitis in humans. Sharing some structural and functional properties with plant viroids, the HDV RNA contains a single open reading frame coding for the only virus protein, the Delta antigen. A number of unique features, including ribozyme activity, RNA editing, rolling-circle RNA replication, and redirection for a RNA template of host DNA-dependent RNA polymerase II, make this small pathogen an excellent model to study virus-cell interactions and RNA biology. Treatment options for chronic hepatitis Delta are scarce and ineffective. The disease burden is perhaps largely underestimated making the search for new, specific drugs, targets, and treatment strategies an important public health challenge. In this review we address the main features of virus structure, replication, and interaction with the host. Virus pathogenicity and current treatment options are discussed in the light of recent developments.publishersversionpublishe

    Phenomenon of Cloning and specificity of its usage

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    Cloning is studied by different branches of science. Medicine is interested in cloning because of its ability to transplant special tissues and organs, genetics - with the purpose of studying heredity and succession, sociology deals with moral and ethic aspects of the phenomenon. The paper is devoted to the study of cloning, its special features and usage in different spheres of social life. The article represents main types of cloning, specificity of vegetative and animal cloning and problems of its expansion. The paper also demonstrates the actual topic of nowadays studies connected with human cloning and its aftereffects for science and society. The article may be useful for a wide audience and for people, who are interested in studies of cloning and problems of its realization

    Observatory/data centre partnerships and the VO-centric archive: The JCMT Science Archive experience

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    We present, as a case study, a description of the partnership between an observatory (JCMT) and a data centre (CADC) that led to the development of the JCMT Science Archive (JSA). The JSA is a successful example of a service designed to use Virtual Observatory (VO) technologies from the start. We describe the motivation, process and lessons learned from this approach.Comment: Accepted for publication in the second Astronomy & Computing Special Issue on the Virtual Observatory; 10 pages, 5 figure

    Band Calculations for Ce Compounds with AuCu3_{3}-type Crystal Structure on the basis of Dynamical Mean Field Theory I. CePd3_{3} and CeRh3_{3}

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    Band calculations for Ce compounds with the AuCu3_{3}-type crystal structure were carried out on the basis of dynamical mean field theory (DMFT). The auxiliary impurity problem was solved by a method named NCAf2f^{2}vc (noncrossing approximation including the f2f^{2} state as a vertex correction). The calculations take into account the crystal-field splitting, the spin-orbit interaction, and the correct exchange process of the f1f0,f2f^{1} \rightarrow f^{0},f^{2} virtual excitation. These are necessary features in the quantitative band theory for Ce compounds and in the calculation of their excitation spectra. The results of applying the calculation to CePd3_{3} and CeRh3_{3} are presented as the first in a series of papers. The experimental results of the photoemission spectrum (PES), the inverse PES, the angle-resolved PES, and the magnetic excitation spectra were reasonably reproduced by the first-principles DMFT band calculation. At low temperatures, the Fermi surface (FS) structure of CePd3_{3} is similar to that of the band obtained by the local density approximation. It gradually changes into a form that is similar to the FS of LaPd3_{3} as the temperature increases, since the 4f4f band shifts to the high-energy side and the lifetime broadening becomes large.}Comment: 12 pasges, 13 figure

    Alzheimer disease pathology and the cerebrospinal fluid proteome.

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    Altered proteome profiles have been reported in both postmortem brain tissues and body fluids of subjects with Alzheimer disease (AD), but their broad relationships with AD pathology, amyloid pathology, and tau-related neurodegeneration have not yet been fully explored. Using a robust automated MS-based proteomic biomarker discovery workflow, we measured cerebrospinal fluid (CSF) proteomes to explore their association with well-established markers of core AD pathology. Cross-sectional analysis was performed on CSF collected from 120 older community-dwelling adults with normal (n = 48) or impaired cognition (n = 72). LC-MS quantified hundreds of proteins in the CSF. CSF concentrations of β-amyloid 1-42 (Aβ <sub>1-42</sub> ), tau, and tau phosphorylated at threonine 181 (P-tau181) were determined with immunoassays. First, we explored proteins relevant to biomarker-defined AD. Then, correlation analysis of CSF proteins with CSF markers of amyloid pathology, neuronal injury, and tau hyperphosphorylation (i.e., Aβ <sub>1-42</sub> , tau, P-tau181) was performed using Pearson's correlation coefficient and Bonferroni correction for multiple comparisons. We quantified 790 proteins in CSF samples with MS. Four CSF proteins showed an association with CSF Aβ <sub>1-42</sub> levels (p value ≤ 0.05 with correlation coefficient (R) ≥ 0.38). We identified 50 additional CSF proteins associated with CSF tau and 46 proteins associated with CSF P-tau181 (p value ≤ 0.05 with R ≥ 0.37). The majority of those proteins that showed such associations were brain-enriched proteins. Gene Ontology annotation revealed an enrichment for synaptic proteins and proteins originating from reelin-producing cells and the myelin sheath. We used an MS-based proteomic workflow to profile the CSF proteome in relation to cerebral AD pathology. We report strong evidence of previously reported CSF proteins and several novel CSF proteins specifically associated with amyloid pathology or neuronal injury and tau hyperphosphorylation
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