1,720,956 research outputs found
Use of halogenated precursors to define a transcription time window (ttw) after treatment with hypometabolizing molecules.
No full textUse of halogenated precursors to define a transcription time window after treatment with hypometabolizing molecules.
No full textA new method is proposed which combines the high spatial resolution of transmission electron microscopy with information on the dynamics of transcription. Incorporation of two different RNA precursors was used to define a time transcription window on cultured cells treated with hypometabolizing peptides which are known to modulate transcription. This procedure allows detecting a single fibril of newly synthesized RNA in the time range in which it is transcribed
Chitosan nanoparticles can enter the cell nucleus to release a peptide inducing reversible hypometabolic state in HeLa cells.
No full textInduction of an in vitro reversible hypometabolism through chitosan-based nanoparticles.
Full text linkObjective: Chitosan-based nanoparticles (NPs) were prepared to promote intracellular sustained delivery of
the synthetic delta opioid D-Ala(2)-D-Leu(5)-enkephalin (DADLE), prolonging peptide activity and inducing
a safe and reversible hypometabolic state.
Materials and methods: NPs were prepared by combining ionotropic gelation and ultrasonication treatment.
NP uptake studies and the effects of encapsulated DADLE on HeLa cells proliferation were tested by
transmission electron microscopy (TEM) analysis, by immuno-fluorescence and immuno-cytochemistry.
Results: DADLE-loaded NPs are produced with suitable characteristics, a satisfactory process yield
(55.4%2.4%) and encapsulation efficiency (64.6%2.1%). NPs are effective in inducing a hypometabolic
stasis at a 104M DADLE concentration. Moreover, as seen from the immunofluorescence study, the effect
persists through the recovery period (72 h). Indeed, NPs labelled by anti-enkephalin antibody inside cell
nucleus reassert that the in vivo release of the peptide can be prolonged with respect to the case of free
peptide supply.
Conclusion: The nanoparticulate drug delivery system described seems to be effective in inducing and
prolonging a sort of hibernation-like state in the cells
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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