1,721,428 research outputs found
SUPERFICI NANOSTRUTTURATE E RIGENERAZIONE NERVOSA PERIFERICA
No full textIl gold standard nel trattamento delle grosse perdite di sostanza nervosa rimane l’innesto autologo che, con la presenza cellule di Schwann, offre fattori neurotro ci e substrati d’adesione per la crescita asso- nale. Per i limiti di tale metodica (danno al sito donatore, doppio accesso chirurgico ed indisponibilità d’ingenti quantità d’innesti) sono state proposte delle alternative come la tubulizzazione (biologica o sintetica). Recentemente è stata data importanza all’interazione fra le cellule (nervose e gliali) e gli sti- moli sici e chimici provenienti dall’ambiente extracellulare. L’ingegneria tissutale è oggi in grado di produrre scaffold con strutturazione super ciale delle dimensione dei nanometri in grado di riprodurre le caratteristiche della matrice extracellulare (ECM). La versatilità con cui possono essere prodotte que- ste super ci e la loro possibile funzionalizzazione con molecole biologiche (peptidi/proteine, fattori di crescita, ecc.), può essere applicata nel trattamento delle perdite di sostanza nervosa (>30 mm) con l’o- biettivo di realizzare un device a struttura tubulare con un’adeguata interfaccia nervo-scaffold, essibile, biocompatibile, e non immunogenica.Today, the treatment of big nerve gaps is the autologous nerve graft (with Schwann cells, it provides neurotropic factors and adhesion substrates that aid the axonal growth). The limits of this technique are the donor side damage, the need of double surgical access and unavailability of large amounts of grafts. Some authors proposed alternatives like tubulization (biological or synthetic tubes). Recently, the rese- archers focus on the interaction between the cells (nerve and glial cells) and the physical and chemical signals risen from the extracellular environment.
Tissue engineering is able to produce scaffolds with some degree of micro/nano topographical noise that reproduce the directional stimuli determined by the extracellular matrix (ECM). Moreover these gratings can be functionalized with biological molecules, peptides, proteins, growth factors, ecc.
We can consider these new surfaces like new possibilities for successful implant strategies in the context of peripheral nerve-regeneration devices, especially for the big nerve gap (>30 mm)
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
Effects of prenatal exposure to diclofenac sodium and saline on the optic nerve of 4- and 20-week-old male rats: A stereological and histological study
Full text linkKaplan, Suleyman/0000-0003-1477-5002; Turkmen, Aysin/0000-0003-0330-9655; Geuna, Stefano/0000-0002-6962-831XWOS: 000329846700009PubMed: 23977957We investigated the effects of diclofenac sodium (DS) on development of the optic nerve in utero. Pregnant female rats were separated into three groups: control, saline treated and DS treated. Offspring of these animals were divided into 4-week-old and 20-week-old groups. At the end of the 4th and 20th weeks of postnatal life, the animals were sacrificed, and right optic nerves were excised and sectioned for ultrastructural and stereological analyses. We demonstrated that both DS and saline produced structural and morphometric changes in the total axon number and density of axons, but decreased the myelin sheath thickness in male optic nerves. All ultrastructural and morphometric features were well developed in 20-week-old rats. We showed that development of the optic nerve continues during the early postnatal period and that some compensation for exposure to deleterious agents in utero may occur during early postnatal life
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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