1,720,965 research outputs found
Selective protein trapping within hybrid nanowells
No full textNanostructured surfaces offer a great deal in view of the control of biological processes at subcellular level. An innovative methodology has been developed to fabricate large-scale hexagonally close-packed arrays of polymer/gold nanowells of tunable diameter and depth, ranging between about 70 and 100 nm (diameter) and 15 and 40 nm (depth). Nanowell volumes down to 0.3 attolitres and nanowell densities as high as ∼109 wells per cm2 could also be demonstrated. The present paper investigates the main features of protein trapping processes within the obtained nanowell arrays. Selective protein trapping, also involving orientation and biofunctionality changes, appears to be induced by the nanoconfinement. Nanomorphology measurements and antibody preferential linkages are demonstrated for human serum albumin versus lysozyme, the first being efficiently trapped within the nanocavities and the second being preferentially deposited outside them. The selective protein-dependent trapping/untrapping within the nanowells is discussed in terms of the variation in the out-diffusion coefficients of the biomolecules entering the nanowells, either as a function of the matching/mismatching of the biomolecules and nanocavity dimensions, or, alternatively, owing to the drastic conformational changes due to nanoconfinement. In this case, the trapping of large and soft human serum albumin is privileged with respect to the small and hard lysozyme. Furthermore, the observed peculiar antibody response to the confined proteins is accounted for in terms of the enhancement of their biological response following the modified accessibility of the key epitopes, which in turn suggests drastic conformational changes
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Probing the outermost layer of thin gold films by XPS and density functional theory
Get PDFThis work examines gold thin films of various thicknesses varying from 5 to over 100 nm along a 7 cm distance to investigate the effect on the surface sensitivity of the XPS Au4f signal. Increasing the relative intensity of the surface XPS signal can be useful for studying properties of the surface atoms in case of functionalized gold, and for shedding light on reactions occurring at the interface with the metal surface as well as adsorption geometry. The surface-to-bulk signal ratio increased with decreasing thickness for thicknesses greater than 15 nm. Below this value, the intensity of the surface signal decreased. The binding-energy shift of the surface component with respect to the bulk component was found to be in agreement with that calculated by density functional theory (DFT). The calculated shift was found to be essentially unaffected, whether or not final-state effects were included. KPFM was also performed to investigate correlations between the measured work function and the surface/bulk BE shift, revealing that the contact potential difference changes with thickness because of the influence of the substrate. Gradients were prepared by a novel evaporation method, by template stripping, and by photolithography, yielding stripes of increasing thickness in the same sample
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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