1,720,957 research outputs found
An amperometric glucose biosensor prototype fabricated by thermal inkjet printing
No full textThe prototype of an amperometric glucose biosensorwas realized by thermal inkjet printing using biological and electronicwater-based inks,
containing a glucose oxidase (GOD) from Aspergillus niger and the conducting polymer blend poly(3,4-ethylenedioxythiophene/polystyrene
sulfonic acid) (PEDOT/PSS), respectively. The biosensor was fabricated microdepositing PEDOT/PSS and GOD, in sequence, on ITO-glass,
by a commercial inkjet printer, with the help of a commercial software. High density microdots matrices were so-realized, with a calculated
resolution of about 221×221 dpi (dot per inch). By means of a rapid and easy assay it was demonstrated that no activity loss occurred upon
the printing of GOD, despite of the use of a thermal printhead. The device was encapsulated in a semipermeable membrane of cellulose
acetate, applied by dip-coating, in order to prevent dissolution of the enzyme and/or PEDOT/PSS in water. The preliminary response of the
electrode was measured in an aqueous glucose solution in the presence of ferrocenemethanol (FeMeOH) as a mediator, and resulted linear up
to 60mM in glucose. The best sensitivity value achieved was 6.43AM−1 cm−2 (447 nAM−1 U−1 cm−2). The characteristics of the device,
and the possible performance improvements have been analyzed and discussed. The reported findings indicate that inkjet printing could be a
viable instrument for the easy construction of a working biosensor via direct digital design using biological and conductive polymer based
inks. Such an approach may be seen as an example of “biopolytronics”
Thermal Inkjet Technology for the Microdeposition of Biological Molecules as a Viable Route for the Realization of Biosensors
No full textRecent progress in inkjet printing of parts of biosensors are highlighted,
with particular reference to the printing of biologically active molecules.
We describe a system constituted by a thermal inkjet printer, adapted to
layering a bidimensional array of dots [701 701 dots per inch] on solid supports. The printer was used to depose a b-galactosidase (GAL)-
containing ink on a polyester sheet, with dots obtained from
10 pL drops, each drop containing in turn 6 pg of enzyme. The activity
of GAL after the preparation was determined using a colorimetric probe
(Brilliant Blue FCF). The activity loss of the microdeposed enzymes was
found to be around 15%, showing that the 2 msec-lasting thermal shock
experienced by the biomolecule into the printhead nozzle affects to a
lesser extent the activity of the thermal inkjet deposited enzyme. In
conclusion, the most recent findings of our group in this line are depicted,
and a view of possible future developments of the “biopolytronics” field
is outlined
Thermal inkJet microdeposition of PEDOT:PSS on ITO-coated glass and characterization of the obtained film
No full textIn view of direct inkjet printing of low-cost sensors, we describe here the thermal printing of a thin film of a commercially available
conjugated polymer (poly(3,4-ethylenedioxythiophene):polystyrene sulfonic acid, PEDOT:PSS). The printed film has been investigated by
optical microscopy, AFM and cyclic voltammetry. The results have been compared to the ones obtained for a continuous film of the same
polymer deposed by spin-coating. No appreciable differences were noted between the electrochemical behaviour of the two samples, indicating
that the thermal printing of the polymer did not alter appreciably the material properties. Our findings indicate that the thermal printing route
may be then a good alternative for the controlled deposition of thin films of conjugated polymers
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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