1,720,973 research outputs found
Fused deposition modelling supporting the design of in vitro models of diseased muscular tissues
Full text linkL'abstract è presente nell'allegato / the abstract is in the attachmen
In vitro models of human cardiac fibrotic tissue on ‘bioartificial’ scaffolds
Full text linkCardiac infarction is a global burden worldwide that leads to fibrotic and not contractile myocardial tissue. In this work, in vitro models of infarcted tissue were developed as tools to test novel therapies for cardiac regeneration in the future. Human cardiac fibroblasts were cultured on scaffolds, with different compositions and architectures, as to mimic structural and chemical features of infarcted cardiac tissue. Early findings from in vitro cell tests were reported, showing an enhancement of cell attachment and proliferation in the case of “bioartificial” scaffolds, i.e. scaffolds based on a synthetic and a bioactive polymer
3D bioartificial stretchable scaffolds for an in vitro model of fibrotic cardiac tissue
Full text linkFibrous bioinks for the bioprinting of anisotropic scaffolds with micro-and nanoscale organization as a novel approach for in vitro skeletal muscle engineering
Full text linkReplicating skeletal muscle architecture remains challenging in 3D bioprinting, as
conventional bioinks lack multiscale directional cues. Herein, we propose a next-
generation fibrous bioink composed of fragmented electrospun gelatin fi bers
(f-GFs), uniformly embedded in an alginate/gelatin hydrogel matrix (f-ALG/Gel).
Upon microextrusion bioprinting, shear-induced f-GF alignment enabled the
fabrication of microfilament-based scaffolds with intrinsic anisotropy. The resulting
constructs exhibited high shape fidelity, favorable viscoelastic properties, and
physiologically relevant stiffness (Young’s modulus: 16.1 ± 1 .7 kPa). In vitro studies
using C2C12 murine myoblasts demonstrated that the embedded f-GFs provided
strong topographical guidance, enhancing cell alignment and myogenesis. After
14 days of culture, the f-ALG/Gel scaffolds supported a 2.5-fold increase in myotube
fusion index and length, alongside reduced angular dispersion. These effects
were achieved without the need for biochemical induction with a differentiation
medium, underscoring the key role of structural cues at the micro- and nanoscale in
C2C12 differentiation and maturation. In conclusion, this work proposes a scalable,
cell-compatible strategy to recapitulate the hierarchical organization of skeletal
muscle tissue within 3D-printed constructs. The platform holds broad potential for
applications in regenerative medicine, skeletal muscle tissue modeling, and the
engineering of cultured meat
Three-Dimensional Microfibrous Scaffold with Aligned Topography Produced via a Combination of Melt-Extrusion Additive Manufacturing and Porogen Leaching for In Vitro Skeletal Muscle Modeling
Full text linkSkeletal muscle tissue (SMT) has a highly hierarchical and anisotropic morphology, featuring aligned and parallel structures at multiple levels. Various factors, including trauma and disease conditions, can compromise the functionality of skeletal muscle. The in vitro modeling of SMT represents a useful tool for testing novel drugs and therapies. The successful replication of SMT native morphology demands scaffolds with an aligned anisotropic 3D architecture. In this work, a 3D PCL fibrous scaffold with aligned morphology was developed through the synergistic combination of Melt-Extrusion Additive Manufacturing (MEAM) and porogen leaching, utilizing PCL as the bulk material and PEG as the porogen. PCL/PEG blends with different polymer ratios (60/40, 50/50, 40/60) were produced and characterized through a DSC analysis. The MEAM process parameters and porogen leaching in bi-distilled water allowed for the development of a micrometric anisotropic fibrous structure with fiber diameters ranging from 10 to 100 μm, depending on PCL/PEG blend ratios. The fibrous scaffolds were coated with Gelatin type A to achieve a biomimetic coating for an in vitro cell culture and mechanically characterized via AFM. The 40/60 PCL/PEG scaffolds yielded the most homogeneous and smallest fibers and the greatest physiological stiffness. In vitro cell culture studies were performed by seeding C2C12 cells onto a selected scaffold, enabling their attachment, alignment, and myotube formation along the PCL fibers during a 14-day culture period. The resultant anisotropic scaffold morphology promoted SMT-like cell conformation, establishing a versatile platform for developing in vitro models of tissues with anisotropic morphology
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
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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