1,720,975 research outputs found
Infrared HP study of protein folding and aggregation @ the SISSI Elettra beamline
No full textFourier transform infrared spectroscopy (FTIR) coupled with High Hydrostatic Pressure technology
is a suitable technique to investigate unfolding/misfolding processes providing useful information
on the kinetics of aggregation of proteins. Since HHP doesn't affect the enthalpic contribution to
the Gibbs free energy, it is able to perturb the secondary structure of proteins in a reversible way .
The principle governing pressure effects is that it tends to shift a system towards the state that
occupies the smallest volume, it causes the electrostriction of charged and polar groups, the
elimination of packing defects, and the solvation of hydrophobic groups. Cavities and packing
defects are expected to be major contributors to volume changes and their presence will make the
system more susceptible to pressure unfolding/dissociation. Because high pressure allows
stabilization of folding intermediates such as molten-globule conformations, this method provides
an unique opportunity for their characterization. We present here latest developments in the set up
of a high pressure infrared facility for the study of protein folding misfolding and aggregations at
the SISSI beamline at Elettra
Unravelling the Structure of Protic Ionic Liquids with Theoretical and Experimental Methods: Ethyl-, Propyl- and Butylammonium Nitrate Explored by Raman Spectroscopy and DFT Calculations
No full text
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
Evolution of past esame technology and metal conservation issues: the case of two Byzantine style bindings
No full textThe results of a Raman spectroscopic study of the cloisonne’ and basse-taille enamels, which beautify two Byzantine style
bindings from the Marciana Library (Venice), namely the Lat. III,111 and the MsGR.I.53 codexes, are presented in this work. The
first binding dates back to the 13th century and was subject to an early restoration work in the 14th century, when new enamels
substituted four originals. The second binding, from the 15th century, shows a lower number of enamels, all originals, and with a
larger color palette. The white and yellow enamels of both codexes were successfully characterized and the red ones, where
hematite was not used. Interestingly the white and yellow color of the 13th century enamels of the Lat. III,111 codex has been
obtained by an ancient technique of the glass technology, which was already obsolete in the 13th century, and is based on the
use of calciumantimonate and Naples yellow. Thewhite color in the other binding’s enamels have been instead obtained by using
cassiterite, according to the tradition of the time. Cassiterite was also mixed to Naples yellow in the enamels of the MsGR.I.53
codex, to change the yellow hue. The identification of agents determining some colors is instead uncertain or not feasible by
Raman spectroscopy. The transparency of the 14th century enamels of the Lat. III,111 codex has allowed the comparison of metal
degradation below the enamels and in regions exposed to the atmosphere
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
Aggregation properties of proteins under high pressure
No full textFourier transform infrared spectroscopy (FTIR) coupled with High Pressure (HP) techniques is a suitable tool to investigate
unfolding/misfolding processes providing useful information on the
kinetics of aggregation of proteins[1]. Since HP affects only the volume contribution to the Gibbs free energy, it is able to perturb the structure of proteins in a reversible way [2][3]. The principle governing pressure
effects is that it tends to shift a system towards the state that occupies the smallest volume, it causes the electrostriction of charged and polar groups, the elimination of packing defects, and the solvation of
hydrophobic groups. Cavities and packing defects are expected to be
major contributors to volume changes and their presence will make the
system more susceptible to pressure unfolding/dissociation. Because
high pressure allows stabilization of folding intermediates such as
molten-globule conformations, this method provides an unique
opportunity for their characterization. We present here latest
developments in the set up of a high pressure infrared facility for the
study of protein folding misfolding and aggregations at the SISSI beamline at Elettra
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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