1,721,019 research outputs found
A Hydrogel Based on a polyaspartamide: Characterization and Evaluation of In-vivo Biocompatibility and Drug release in the Rat.
No full textAbstract
This paper deals with the characterization of a new microparticulate hydrogel obtained by gamma irradiation of α,β-poly[N-(2-hydroxyethyl)-dl-aspartamide] (PHEA).
When enzymatic digestion of PHEA hydrogel was evaluated using various concentrations of pepsin and α-chymotrypsin no degradation occurred within 24 h. In-vivo studies showed that this new material is biocompatible after oral administration to rats. PHEA hydrogel was also studied as a system for delivery of diflunisal, an anti-inflammatory drug. In-vitro release studies in simulated gastrointestinal juice (pH 1 or 6.8) showed that most of the drug was released at pH 6.8. In-vivo studies indicated that diflunisal-loaded PHEA microparticles significantly improved the gastric tolerance and oral bioavailability of the drug in comparison with free diflunisal.
These results suggest the potential application of PHEA hydrogel as a new delivery system for the oral administration of anti-inflammatory drugs.</jats:p
Generalized and focal dystonic syndromes: possible therapy with salmon calcitonin.
No full textWe report that repeated administration of salmon calcitonin (20-40 micrograms daily for 30 days) improves dystonic symptoms in patients affected by idiopathic torsion dystonia, blepharospasm-oromandibular dystonia syndrome or writer's cramp syndrome. These results support the suggestion that calcitonin may act at central level influencing the extrapyramidal motor system
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
PRODUCTION VIA MICROFLUIDICS OF FIBRILLAR AND NANOMETRIC BIOMATERIALS FOR REGENERATIVE MEDICINE AND DRUG DELIVERY POURPOSES
No full textMicrofluidic technique offers mild operating conditions suitable for fabrication of fibers and
cell encapsulation and can be applied for controlled production of nanometric biomaterials1
.
Ionotropic polysaccharides are routinely employed for microfluidics. To be processed, nonionotropic polysaccharides, such as Hyaluronic Acid (HA), should be chemically crosslinked during
fabrication2
. In order to avoid chemical crosslinking, we designed an ionic strenght sensible HA
derivative suitable for microfluidics2
. Here we describe the use of such HA derivative for
fabrication of fibrillar and nanometric biomaterials for regenerative medicine and drug delivery
applications. For muscle tissue regeneration purposes, 3D microfibrillar scaffolds were produced
and characterized as guidance for Aortic Smooth Muscle cells (AoSMCs). Nanoparticles were
produced and characterized as drug delivery systhems for treatment of retinal angiogenic
pathologies
Fibrillar polymeric patches suitable for wound healing
No full textMultilayered scaffolds can be designed to improve soft material applicability for regenerative medicine purposes. Excellent results can be obtained by combining the main characteristics of the biopolymers and giving a specific function to each layer. A microfluidic-assisted electrospinning process is an elegant arrangement between two fiber fabrication techniques that defines finely every portion of an electrospun scaffold. Unlike classic electrospinning technique, multiple flows can be carefully monitored and separated in real time using microfluidic sensors. This method allows users to establish anisotropic properties to scaffolds, in other words it is possible to modulate gradients by changing flow parameters. In this regard, patches consisting of biodegradable and biocompatible random copolymer polycaprolactone/polyurethane with two different technique had been produced and compared. Working conditions of both technique, classic and microfluidic-assisted electrospinning, had been found. Results showed benefits of microfluidic and electrospinning coupling, such as smaller diameter of fibers, homogeneity of patch and higher percent yield. Next goal is to combine polycaprolactone/polyurethane layer with a polysaccharide layer. Indeed, in wound healing application, it could be useful to obtain a patch with two sides, one of them exerts its therapeutic function releasing an active ingredient (e.g. drug, growth factor) while the other side gives impermeability to the patch, as a skin substitute
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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