1,721,232 research outputs found
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
Design and fabrication of graphene/lipid nanostructured interfaces for applications in membrane protein biosensing
Full text linkPlasma membranes, or cytoplasmatic membranes, are the reaction fields of many biological reactions involved in diseases, and an active barrier for the transportation of information and materials between the inside and outside compartments of cells. Lipid bilayers are the fundamental structure of cell membranes. Examining the functional behavior of lipids and proteins and their ensemble by using artificial lipid bilayers integrated in biosensors is important in order to determine the physical and chemical processes involved in cell membrane reactions, that are relevant in a wide range of biomedical applications. By using supported lipid bilayers (SLBs) on graphene-based substrates, it is possible to develop novel biosensors able to obtain molecular information from membrane proteins embedded in lipid bilayers: the graphene acts as the transducer of the electrical signals and the phospholipidic bilayers with embedded molecular proteins form the receptor layer. The main objectives of this thesis are the design and optimization of the interactions between graphene and lipid bilayers, through the analysis of the fabrication process of graphene, its surface treatments and how these affects the formation of supported lipid membranes. These are essential steps aiming at manufacturing a novel properly designed biosensing platform with integrated membrane proteins. Nanomaterials can play a very significant role in the development of the next generation of biosensors, since they can help to address some of the key issues in the development of biosensors. Graphene is a carbon-based nanomaterial that has recently attracted most interest due to its unique electronic properties, arising from its crystal structure, which result in a extremely low noise level and an increased signal-to-noise ratio. The fabrication of biosensors based on SLBs on graphene requires the study and optimization of the building blocks of the sensor and of the interface between them. The formation of SLBs is strongly influenced by the physical and chemical properties of the underlying substrates. Then, in order to induce the formation of lipid bilayers possessing a sufficient stability for practical biosensing applications, the wetting properties of the supporting layer should be investigated. Since graphene is a hydrophobic material, the introduction of defects on the surface both by heat treatments or functionalization have been investigated
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
Role of N-Carboxybutyl chitosan in the repair of the meniscus
No full textN-Carboxybutyl chitosan obtained from crustacean chitin was used to assist the spontaneous tissue repair of the meniscus, which is usually of extreme difficulty. Results indicate that this natural modified polysaccharide is well-tolerated at the articular synovial level. It also favors and stimulates the repair processes which do not take place spontaneously in the meniscus. N-Carboxybutyl chitosan, therefore, plays a role which helps in repairing meniscal lesions.
N-Carboxybutyl chitosan obtained from crustacean chitin was used to assist the spontaneous tissue repair of the meniscus, which is usually of extreme difficulty. Results indicate that this natural modified polysaccharide is well-tolerated at the articular synovial level. It also favors and stimulates the repair processes which do not take place spontaneously in the meniscus. N-Carboxybutyl chitosan, therefore, plays a role which helps in repairing meniscal lesions
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