1,721,031 research outputs found
Bioanalysis in Femtoliter Scale Printed Artificial Systems
No full textPrinting has fueled the development of a new class of artificial biosystems for the qualitative and
quantitative determination of bioanalytes [1]. In particular, the multiscale organization (from nanometers
to millimeters) and multiplexed molecular composition (DNA, proteins, lipids, polymers) of such platforms
enable the determination of molecular interactions in conditions mimicking/redesigning those of the living
systems. Since the development of microarrays platforms [2], the downsizing of the “analyzable” feature
down to femtoliter (fL) scales has permitted to develop new researches in the field of molecular
condensates/confinement. Herein, two relevant examples of fL-scale systems will be discussed,
highlighting their applications in bioanalysis. The first one includes molecular inks containing DNA
nanoswitches or CYP2E1 catalyzed enzymatic reactions produced by inkjet printing fL-scale compartments
into mineral oil drops [3]. The downscaling triggers the organization of a confined environment at the
water/oil interface, resulting in up-concentration effects and molecular crowding. The employ of
fluorescence lifetime imaging permits to analyze downscaling induced effects, namely up-concentration,
heterogeneity and molecular proximity. The second example consists in fL-scale droplets
produced by microchannel cantilever spotting (μCS) of inks containing single strand DNA (ssDNA) into
porous substrates (nylon), resulting in oligonucleotides microarrays for sensing applications [4]. The
downscaling to fL-scale imbibition into porous substrates highlights an intriguing and complex process
controlled by the interplay of spreading, evaporation and capillary effects, being facilitated by glycerol
additive in the ink. The DNA sequences functionality is demonstrated by hybridization with a fluorolabeled
complementary sequence, producing a double strand sequence (dsDNA). The signal distribution in the spot
is homogeneous and allows for the optical detection of spotted oligonucleotides down to few tents of
zeptomoles
Structural study of meso-octaethylcalix[4]pyrrole Langmuir-Blodgett films used as gas sensors
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
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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