38 research outputs found
Simplest Prussian-blue deposition from ferric ferricyanide solution by a reducing Ag spot put onto an ITO substrate
This article was published in the Journal of Solid State Electrochemistry [© Springer-Verlag] and the definitive version is available at: http://dx.doi.org/10.1007/s10008-012-1811-7Prussian-blue (PB) film for electro-chromism can be electro-deposited on to an electrode (usually tin-doped indium oxide/glass) either directly from a PB colloid or from ferric ferricyanide in a two-electrode electro-chemical cell by applying a reductive potential. Alternatively, a “sacrificial” electron-producing silver flag electrode in the solution, when connected to the PB-receiving electrode, can effect the required reductive deposition. A silver spot, here innovatively applied as silver paint directly onto the deposition electrode, produces PB film on immersion in the iron(III)(III) solution, obviating the separate counter-electrode method
A computational analysis of the dynamic roles of talin, Dok1, and PIPKI for integrin activation
Integrin signaling regulates cell migration and plays a pivotal role in
developmental processes and cancer metastasis. Integrin signaling has been
studied extensively and much data is available on pathway components and
interactions. Yet the data is fragmented and an integrated model is missing. We
use a rule-based modeling approach to integrate available data and test
biological hypotheses regarding the role of talin, Dok1 and PIPKI in integrin
activation. The detailed biochemical characterization of integrin signaling
provides us with measured values for most of the kinetics parameters. However,
measurements are not fully accurate and the cellular concentrations of
signaling proteins are largely unknown and expected to vary substantially
across different cellular conditions. By sampling model behaviors over the
physiologically realistic parameter range we find that the model exhibits only
two different qualitative behaviours and these depend mainly on the relative
protein concentrations, which offers a powerful point of control to the cell.
Our study highlights the necessity to characterize model behavior not for a
single parameter optimum, but to identify parameter sets that characterize
different signaling modes
Nafion® as advanced immobilisation substrate for the voltammetric analysis of electroactive microparticles: the case of some artistic colouring agents
Voltammetry of microparticles is applied to characterise
and to identify solid analytes of interest in the field
of cultural heritage. Nafion® is used for the immobilisation
of solid microparticles onto the surface of a glassy carbon
electrode by exploiting the deposition onto the electrode
surface of a micro-volume of a suspension of the microsample
in polymeric solution. Cyclic voltammetry and
square wave voltammetry are applied to characterise and
to identify the microparticles immobilised in the Nafion®
coating. The analyte studied in this work is Prussian Blue as
a typical inorganic pigment, with a relatively simple electrochemical
behaviour. The proposed method is applied to a
sample of Venetian marmorino plaster. The performance of
Nafion® for this analysis is compared with that of the
polymer Paraloid B72
Online network organization of Barcelona en ComĂş, an emergent movement-party
Abstract The emerging grassroots party Barcelona en ComĂş won the 2015 Barcelona City Council election. This candidacy was devised by activists involved in the Spanish 15M movement to transform citizen outrage into political change. On the one hand, the 15M movement was based on a decentralized structure. On the other hand, political science literature postulates that parties develop oligarchical leadership structures. This tension motivates to examine whether Barcelona en ComĂş preserved a decentralized structure or adopted a conventional centralized organization. In this study we develop a computational methodology to characterize the online network organization of every party in the election campaign on Twitter. Results on the network of retweets reveal that, while traditional parties are organized in a single cluster, for Barcelona en ComĂş two well-defined groups co-exist: a centralized cluster led by the candidate and party accounts, and a decentralized cluster with the movement activists. Furthermore, results on the network of replies also shows a dual structure: a cluster around the candidate receiving the largest attention from other parties, and another with the movement activists exhibiting a higher predisposition to dialogue with other parties