1,721,080 research outputs found
Unravelling the molecular mechanism of Sorcin (SOluble Resistance-related Calcium binding proteIN)-dependent resistance to chemotherapeutic drugs in cancer and its network of interaction
Full text linkSorcin is calcium-binding oncoprotein overexpressed in several human tumors, is a marker of Multi-Drug Resistance (MDR), is highly expressed in chemoresistant cell lines, and confers MDR when overexpressed. Sorcin gene is in the same amplicon of glycoprotein-P (mdr1) and its silencing increases cancer cell sensitivity to chemotherapeutic drugs.
Recently we solved the crystal structure of Sorcin in the apo and calcium-bound forms. Upon calcium binding, a large conformational change occurs, with the exposure of hydrophobic surfaces, that allows Sorcin interaction with molecular targets, some of them unravelled by a cutting-edge technique called Proteomic Peptide Phage Display (ProPPD).
To elucidate Sorcin-dependent chemoresistance mechanisms, we:
- used H1299 lung cancer cells, which express high amount of Sorcin;
- silenced Sorcin expression through siRNA;
- treated cells with doxorubicin to elucidate changes in the uptake process and in the biological response;
- tested Sorcin affinity for doxorubicin through Surface Plasmon Resonance and fluorimetry experiments;
-solved the crystal structure of doxorubicin-bound Sorcin.
Our results show that, by direct and specific binding of doxorubicin, Sorcin can act as a buffer for the drug in the cytoplasm, enhance its accumulation outside the nucleus and then its extrusion through MDR1 pump. Indeed Sorcin silencing, in our cancer cells, increases the sensitivity towards the chemotherapeutic drug and subsequently cell death upon treatment
Synthesis and organic functionalization approaches for magnetite (Fe3O4) nanoparticles
Full text linkSeveral new techniques are invented in recent years to attach organic, bio-organic functionalities to the nanostructures such as the nanoparticles. This approach of adding surface reactivity to the particles enables to tune the properties and reactivity of the resulting hybrid monolayer protected nanoparticles. Magnetic iron oxide nanoparticles of various sizes are reported which bears different organic or polymeric groups. In the present note we have revised the important methods of synthesis of magnetite (Fe3O4) nanoparticles and highlighted the most common strategies for the functionalization of these nanoparticles with organic compounds from very recent literature. This short note will help the students and researchers to screen and choose methods for the synthesis and functionalization of magnetite nanoparticles. © 2012 VBRI Press
I metalloceni: una scatola a sorpresa?
No full textUn recente articolo, dal titolo “Group 4 Transition Metal Sandwich Complexes: Still Fresh after Almost 60 Years”, ha fatto il punto sull’attualità della ricerca su questa famiglia di composti metallorganici sottolineando quanto essa sia più che mai vitale e di interesse per tutti i chimici che si occupano di sintesi e catalisi. in particolare ci occuperemo delle relazioni fra metalloceni e polimerizzazion
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
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