1,720,959 research outputs found
Laser-induced fabrication of doped-graphene based on collagen for bone tissue engineering scaffold applications
No full textElectro-active scaffolds play an important role in bone tissue engineering applications, serving as physical substrates for cell proliferation and osteogenic differentiation, ultimately realizing new bone regeneration. This paper discusses a novel strategy to synthesize graphene through laser-induced surface doping, using bone collagen as the carbon source, serving as a key functional filler to be combined with biocompatible, biodegradable poly(ε-caprolactone) (PCL), for the fabrication of the next generation electro-active bone tissue engineering scaffolds. Scaffolds are fabricated through material-extrusion additive manufacturing. The developed graphene is proven to present a significant enhancement effect on surface and mechanical properties over the conventional graphene material
3D-printed graphene and graphene quantum dot-reinforced polycaprolactone scaffolds for bone-tissue engineering
No full textThe regeneration of large-scale bone loss due to accidents, trauma, diseases, or tumor resection is still a critical clinical challenge. With the development of additive manufacturing technology and advanced biomaterials, 3D-printed biocompatible synthetic polymer scaffolds have been widely studied for their key roles in supporting bone tissue regeneration. Scaffold aims to provide mechanical properties that match the host bone as well as biological activities that can effectively promote cell proliferation and differentiation, ultimately facilitating bone tissue regeneration. Due to its unique biocompatibility and biodegradability, polycaprolactone (PCL) becomes one of the dominant synthetic polymeric materials considered for scaffold fabrication. However, using PCL alone presents insufficient mechanical properties; thus, different functional fillers have been added to modulate both the mechanical and biological performance of fabricated scaffolds. Among all functional fillers, carbon nanomaterials, particularly graphene (G), have shown an emerging trend. Graphene quantum dots (GQD), a member of the graphene family, are regarded as an ideal next-generation functional filler for scaffold fabrication. It presents high solubility in water, controllable dose-dependent cytotoxicity similar to that of G, and unique biological properties benefiting from smaller sizes. Current research using GQD for tissue engineering applications is limited, and the systemic comparison between G and GQD at different concentrations is also missing. This study, for the first time, evaluates and compares the impact of incorporating G and GQD into PCL bone tissue engineering scaffolds from surface, thermal, mechanical, and biological perspectives. Results suggested that the addition of both materials under 5 wt % significantly improved both the mechanical and biological performance of PCL scaffolds. Under 3 wt %, PCL/GQD scaffolds presented better compressive strength while maintaining the same level of biological performance compared with PCL/G scaffolds, revealing the strong potential for future in vivo studies and bone tissue regeneration applications
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Design, Fabrication, and Evaluation of Hybrid Polycaprolactone/Graphene Scaffold Based on Additive Manufacturing and Electrospinning
Get PDFElectrospinning and additive manufacturing (AM) are key technologies for fabricating bone tissue engineering scaffolds, each with unique strengths and limitations. Electrospinning produces nanoscale fibers that promote cell attachment and affinity on 2D surfaces but offer limited mechanical strength. In contrast, AM creates 3D scaffolds with enhanced mechanical properties through precise control of topological structures, but the capability to stimulate and guide cell growth is limited compared to electrospun nanoscale fibers. Combining both methods holds potential for next-generation scaffold development with desirable mechanical and biological properties. This study investigates the fabrication of multi-scale and multi-material scaffolds by integrating extrusion-based AM and solution electrospinning. Polycaprolactone (PCL), a biocompatible and biodegradable polymer, served as the base material, while graphene nanosheets were incorporated as functional fillers to enhance mechanical, electrical, surface, and biological properties. Solution electrospinning was first optimized, and hybrid scaffolds were fabricated, with an image-based optimization method, obtaining 87% of the fibres well-aligned with the designed direction. Optimal scaffold composition (PCL nanofibers with 1 wt.% graphene + PCL microfibers with 3 wt.% graphene) was also identified based on 2D mesh characterization results (186% enhancement of the mechanical property and 23% enhancement of the cell proliferation result, compared with neat PCL). The findings demonstrate the potential of this hybrid fabrication approach for developing advanced polymer-carbon nanomaterial scaffolds for bone tissue regeneration applications.Rosetrees Trust UK [CF-2023-I-2\103]University of ManchesterSao Paulo Research FoundationMinistry of National Education of the Republic of Turkey (T.C.MEB)The authors wish to acknowledge Rosetrees Trust UK for the Continuation Funding (Ref: CF-2023-I-2\103), and the funding from SPRINT Joint Research Scheme between The University of Manchester and The Sao Paulo Research Foundation. Mustafa Tugrul Ucan would like to acknowledge the funding from the Ministry of National Education of the Republic of Turkey (T.C.MEB)
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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