1,721,064 research outputs found
Tissue-engineered skin substitutes: an overview
No full textExtensive skin loss and chronic wounds are still a significant challenge to clinicians: even if injured epidermis is normally able to self-renew, deep injuries can cause negative regulation of the wound healing cascade, leading to chronic wound formation. Skin-autografting surgical procedures are often limited by the poor availability of healthy tissue, whereas the use of non-self-tissues for allografts presents some severe risks. Tissue-engineered skin substitutes have recently become viable as a suitable alternative to auto- and allografts. However, biologists, biochemists, and technical engineers are still struggling to produce complex skin substitutes that can readily be transplanted in large quantities. The ambitious goal is now to construct a dermoepidermal substitute that rapidly vascularizes and optimally supports a stratifying epidermal graft on a biodegradable matrix. This review analyzes these aspects in light of the available literature and the authors' experienc
Degradable polymers may improve dental practice
No full textThe use of biomaterials in dentistry is more widespread than in any other medical field in terms of both amount and variety. Most of them were not originally designed for dental applications but for other medical applications or, sometimes, for no medical purposes. Among these materials, biodegradable materials play an important role, especially in bone regeneration and in periodontal surgery. This paper briefly reviews some degradable polymers developed as tools for the treatment of periodontal and bone diseases. We discuss materials previously applied in other industrials contexts, such as polyesters, methylcellulose, and chitosan and we provide perspectives for their use in periodontal regeneration
Biosurfactants prevent in vitro Candida albicans biofilm formation on resins and silicon materials for prosthetic devices.
No full textCurrent advances in the regeneration of degenerated articular cartilage: A literature review on tissue engineering and its recent clinical translation
No full textFunctional ability is the basis of healthy aging. Articular cartilage degeneration is amongst the most prevalent degenerative conditions that cause adverse impacts on the quality of life; moreover, it represents a key predisposing factor to osteoarthritis (OA). Both the poor capacity of articular cartilage for self-repair and the unsatisfactory outcomes of available clinical interventions make innovative tissue engineering a promising therapeutic strategy for articular cartilage repair. Significant progress was made in this field; however, a marked heterogeneity in the applied biomaterials, biofabrication, and assessments is nowadays evident by the huge number of research studies published to date. Accordingly, this literature review assimilates the most recent advances in cell-based and cell-free tissue engineering of articular cartilage and also focuses on the assessments performed via various in vitro studies, ex vivo models, preclinical in vivo animal models, and clinical studies in order to provide a broad overview of the latest findings and clinical translation in the context of degenerated articular cartilage and OA
Effect of air polishing with glycine powder on titanium abutment surfaces.
Full text linkObjective: The aim of the present study was to evaluate morphological changes induced by
glycine powder air polishing on titanium surfaces and its effect on bacteria recolonization in
comparison with sodium bicarbonate powder.
Materials and methods: 5 mm wide and 1 mm thick titanium grade II disks were divided into
three groups of treatments: (i) no treatment; (ii) air polishing with glycine powder; (iii) air
polishing with sodium bicarbonate powder. Specimens were characterized by laser profilometry,
scanning electron microscopy (SEM) and then installed onto removable appliances worn for 24 h
by healthy volunteers. Surface contamination was evaluated using SEM and counting the number
of colony forming units (CFU).
Results: SEM observation revealed an increased roughness with the formation of craters on
samples treated with sodium bicarbonate powder, while not in glycine ones. Statistical analysis
failed to show significant differences of both Ra and Rmax parameters in treated groups. SEM
observation of specimens surfaces, after 24 h of permanence in the oral cavity, showed a higher
contamination of the disks treated with sodium bicarbonate compared with those not treated
(P < 0.05). Conversely, the group treated with glycine showed the lower contamination if
compared with bicarbonate-treated group (P < 0.05).
Conclusions: Air polishing with glycine powder may be considered as a better method to remove
plaque from dental implant because glycine is less aggressive than sodium bicarbonate powder.
Moreover, the use of glycine powder seems to have an active role on the inhibition of bacterial
recolonization of implants in a short test period (24 h). Further studies are needed to demonstrate
the bacteriostatic properties of glycine, envisaged on the basis of reduced contamination of the
disks polished with glycine compared with those not treated
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
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